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DESIGNED AND ENGRAVED FOR RODGERS SCIENTIFIC AGRICULTURE 



PRACTICE AND SCIENCE COMBINED. 



SCIENTIFIC AGRICULTURE, 



OR THE ELEMENTS OF 



CHEMISTKY, GEOLOGY, 

BOTANY AND METEOBOLOGY, 



APPLIED TO 



PRACTICAL AGRICULTURE. 



BY M. M. RODGERS, M. D., 

Author of "^grindtural Che7nistry," "Physical Education and 
Medical Management of Children," 6rc. 

ILLUSTRATED BY NUMEROUS ENGRAVINGS AND A COPIOUS 
GLOSSARY. 



SECOND EDITION, 

STEREOTYPED, REVISED, AND ENLARGED. 



Nature 



ature maintains nniformity in the operation of all Ler laws, and produces nothing bv rhan'"e • 
whenever, therefore, we observe an apparent exception to this principle, it is due to deficiencv of 
knowledf!:e or error m conclusion. And whoever practically disregards this truth, and renu'his 
bopea upon ccntuigent events, will be compelled to correct hu error at his own cost. 



ROCHESTER: 
PUBLISHED BY ^RASTUS DARROW, 

CORNER OF MAIN AND ST. PAUL STREETS. 
NEW YORK : C. M. SAXTON. BOSTON I J. P. JEWETT .fe CO. 

1850. 



Entered according to Act of Congress, in the year of our Lord 
one thousand eight hundred and fifty, 

BY ERASTUS DARROW, 

In the Clerk's office of the District Court of the northern 
District of New York. 



STEREOTYPED BY 
JEWETT, THOMAS, <fe CO., 



BUFFALO, N. Y. 



6,^^"^ 
^^^ 



• TO 

HON. ZADOC PRATT, 

AN EMINENT STATESMAN, 

A ZEALOUS ADVOCATE OF AGRICULTURAL AND MECHANICAL 

IMPROVEMENT, 

AND A LIBERAL PATRON OF SCIENCE, 

THIS VOLUME IS RESPECTFULLY DEDICATED BY 

THE AUTHOR 



PREFACE TO THE FIRST EDITION. 



No apology ought to be required for the appearance of a work like 
this : the importance of the subjects discussed should secure at least an 
impartial examination. 

But from the humiliating consciousness which the author feels of his 
own inability to do justice to so difficult a tJisk, he is induced to say 
something by way of explanation, in order, if possible, to put himself 
upon friendly terms with his readers- The importance of an enter- 
prise, however, furnishes no reason to an incompetent person for attempt- 
ing its prosecution. 

If, after the book has passed the trial of the public prosecutors in 
behalf of science, the critics, — they shall decide against it, the author has 
no alternative, but must plead guilty : neither will he claim indulgence 
on the ground of its being the first offence, or plead, in extenuation of 
his fault, his ignorance of the law in relation to the case. 

But a sincere desire (augmented by personal considerations) to aid iu 
the diffusion and cultivation of science, has induced him to make an 
effort, which may not be regarded by liberal minds as altogether inex- 
cusable. 

The practice of issuing crude and imperfect books, is a fault quite 
too prevalent at the present day : there are already too many mere 
alphabets of science, abridgements, and books of learning made easy ; 
their tendency is to make conceited and superficial scholars, without the 
labor of personal observation and patient study. 

But the elements of any science may be so explained and eirranged, 
as to give a synopsis which may be of much service to the student ; 
and when these elements are learned, he has laid the foundation for 
future advancement by his own observation. Plainness and brevity have 
been studied, and technical language avoided as much as possible ; a 
glossar)' has been appended which explains such technical terms as 



Vi PEEFACE. 

were indispensible. It is needless to say, that a treatise on science 
cannot be entirely divested of all difficulties, and couched in language 
which is at once simple and expressive. 

It was deemed better to give the rudiments of each science, in a 
separate systematic treatise, than to intersperse them through the whole 
book without order or method. A reader will profit more to have the 
principles given in this way, that he may apply them himself, — than he 
will to have a perfect system of agriculture made up of them all, with- 
out systematic arrangement. 

Another advantage of such a book is that the general reader may 
obtain the first principles of Chemistr}% Geology, Botany, or Meteorology, 
without reading a large amount of agricultural science, which, to him, 
may be of little use. 

The author is aware that an amount of matter is embodied in this 
book sufficient to make, when extended and amplified, several such 
volumes : but nearly all books contain much by way of explanation 
and speculation, that could well be omitted. Some things may be found 
in the book which do not appear to have any direct connection with 
practical agriculture ; but a little observation shows that the sciences 
discussed all have such a connection and relation, that to omit any prin- 
ciple would destroy the harmony of the whole system. 

The best authorities have been consulted, — so that whatever may be 
open to criticism must be judged by their testimony. It is desirable 
that the agricultural community, for whose more especial use the book 
is designed, may be disposed to favor the enterprise : with all its faults, 
therefore, it is respectfully committed to them — and the public ; — with 
no claims except to their forbearance, and no means of propitiating their 
favor, bevond its own merits. 

M. M. RODGERS. 

Rochester^ August, 1848. 



PREFACE TO THE SECOND EDITION. 



The first edition of this book has met with so favorable a reception, 
that the autlior and publisher are induced to offer a second, in a much 
enlarged and improved form. Notices from agricultural journals in all 
parts of the United States have been, without a single exception, entirely 
satisfactory. And while we have been flattered with these testimonials 
of favor, we have been accumulating new and valuable matter, by way 
of experimental research, reading, and communication with practical 
farmers. An entire new chapter has been added on the Chemistry of 
the Dairy ; so that the present edition contains a large amount of practical 
matter in a condensed form. The plan of an agricultural book which 
we have adopted, is, so far as we know, original. The four sciences 
which constitute agriculture are treated of separately, because it is much 
easier to deduce the compound from many simple facts, than to separate 
each special case from a mass of generalized facts. Practical application 
has been always kept in view, at the same time the theoretical arrange- 
ment and cleissification of subjects have been preserved. 

II is often objected by farmers, that books are too abstract and scientific 
for practical men ; this depends much upon the amount of intelligence 
such men possess. 

But if we present them with a book which is exclusively confined to 
the details of the most common operations of farming, they object to it, 
on the ground that it is too simple, — and refuse to buy a book which 
only teaches what every farmer knows. 

If practical men object to scientific books, there is no obstacle to their 
writing better ones ; but if they will not write them, they had better be 
written by practical chemists merely, than not be written at all. We 
think the present mode of advancing the art, is the best that can be 
adopted. Let the farmer read, so as to be able to apply science to the 



Vm tREFACE. 



n 



improvement of all practical operations ; and let the chemist and natu- 
ralist investigate the sciences connected with farming, and thus furnish 
matter for reading. Then let them meet and compare notes, and see 
how far practice may be deduced from science. So by means of practicA 
combined with science, a rational system of productive farming may he 
established. A man must not only work, but he must read much also, 
in order to judge rightly of the extent to which he can really make 
•♦book knowledge " available in the art. 

Original investigation and discovery belong mainly to the philosopher ; 
but the practical application of his discoveries belongs to the practical 
man. The discoverer of a new scientific fact is seldom the inventor of 
a machine to which it applies ; and the inventor of a machine is rarely 
the operator of it. Nearly all science is discovered by one cIeiss of men 
and used in practical life by another class. This allows the exclusive 
attention of each to his vocation, and secures greater proficiency in both. 
This fact rests upon the great law which is the basis of all organization 
in civilized society, — viz., "division of labor." Such is the sphit of 
improvement at the present day, that science will force its way into all 
practical branches of business ; and all those which are not conducted 
upon philosophical principles, must ultimately fail, and give place to 
better modes. That this book may contribute its mite to the advance- 
ment of the art of productive agriculture, is the sincere desire of the 
author. 

M. M. RODGERS. 

Rochester, May, 1850. 



AUTHORITIES CONSULTED. 



Kane's Chemistry, 
Fowne's " 

Silliman's " 
Turner's " 

Liebig's Agricultural Chemistry 
Lyell's Geology, 
Hitchcock's " 
Comstock's " 
Gray's Botany, 
Wood's 
Eaton's " 

Muller's Elements of Physics and Meteorology, 
Boussingault's Meteorology, 
Brande's Encyclopedia, 
Lardner's Lectures on Science, 
Encyclopedia Brittanica, 
Johnston's Agricultural Chemistry, 
Boussingault's Rural Economy, 
Thaer's Principles of Agriculture, 
Petzholdt's Lectures on Agriculture, 
Colman's European Agriculture, 
Gardner's Farmer's Dictionary, 

Report of the Regents of the University of K. York, 
Transactions of the N. Y. State Agricultural Society, 
Allen's American Farm Book, 
Brocklesby''s Meteorology, 
Weisbach's Mechanics and Engineering, 
Olmsted's Natural Philosophy. 
1* 



INTRODUCTION. 



Agriculture is doubtless one of the oldest, most honorable 
and important pursuits among ci\'ilized nations. Without it 
the food of man must have been limited to the flesh of wild 
animals and the spontaneous productions of the earth : Com- 
merce could not exist to any extent; the arts and sciences 
would be almost unknown ; and society could not advance in 
improvement beyond a refined state of barbarism. But the 
culture of the soil enables men to produce more of the neces- 
sary food than they require, so that a part only are required 
in this pursuit, while the remainder are enabled to turn their 
talents and ingenuity to some other useful calHng, the products 
or service of which ai-e given to the agriculturist in exchange 
for food. 

This is the orioin of the division of labor, wliich is at the 
foundation of all political economy and true governmental 
policy : this division and subdivision of labor is adopted more 
extensively the more a nation becomes enlightened and pros- 
perous. Without such distribution of pm^suits, little wealth 
could be accumulated by nations or individuals. In order 
that every man should be independent of the services of all 



12 INTRODUCTION. 

others, lie must munufacture and produce every tting with his 
own hands, which, in the social and ci^dlized state of society, 
he receives from them: this would so occupy his time and 
talents that he could only produce the bare necessities of a 
primitive hfe : his food must be obtained by hunting, fishing 
and digging roots, — his clothing, the skins of animals, — his 
shelter, a rude hut, and his only beverage, water. 

From this mode of living, also, the earth must soon contain 
more inhabitants than could subsist on its spontaneous food, 
and part must die of starvation. 

The art of agricidture has been known and successfully 
practiced by some of the oriental nations from remote ages. 

The Chinese appear to have a good practical knowledge of 
soils, and have, by industry and skill in agriculture, sustained 
a population of an almost incredible number: and, although 
they are supposed to be but little removed from barbarism, 
they are said to excel all other nations in the amount of food 
which they produce from a given space of soil. 

That the ancient Romans had an amount of practical know- 
ledge equal to most nations of the present day, is evident from 
the following passages from Virgil's Georgics. Thus in his 
first Georgic he alludes to the rotation of crops, the art of 
manurino' and burnino- land. 

o o 

"Yet shall thy lands through easier labor rear 
Fresh crops by chang-eful produce year by year. 
If rich manure new life and nurture yield, 
And ashes renovate the exhausted field. 
Thus interchanging harvests, earth repair; 
Nor lands unplowed, meantime no profit bear. 
Much it avails to burn the sterile lands. 
And stubble, crackling as the flame expands; 
Whether earth gain fresh strength or richer food. 
Or noxious moisture, forced by fire exude; 
Whether it draw through many an opening ve««. 
Juice to fresh plants that clothe anew the plain» 
Or brace the pores, that previous to the day,- 
Felt the prone sun's intolerable ray, 
To piercing showers the expanded fissure close, 
And the chill north that blisters as it blows." 



INTRODUCTION. 13 

Again in tlie second Georgic we have evidence that they 
studied the nature of, and adapted various crops m different 
qualities of soils. « 

" Now learn the soils, the nature of each field. 
What fruits their varying strength and virtue }ieid: 
Know first, the ungenial hill and barren land. 
Where sterile beds of hungry clay expand. 
And thorns and flints deface the rugged earth. 
Demand the long lived plants palladian birth." 

In the other two Georgics we learn that the Romans 
understood horticulture, gardening, the management of do- 
mestic aniijaals and bees, — and the extermination of noxious 
weeds and insects. Limited as were their mechanical means, 
and their knowledge of chemistry, geology and botany,— still 
their skill and success would seem to exceed that of aoricultu- 
rists of the present day ; and in fact we may almost believe 
that the practical knowledge of farming has retrograded since 
that time. If this is the case, it cannot be because science 
has been detrimental to modern practice, — but is rather owing 
to their close observation of nature, and their attentive indus- 
try. It is no argument against the art of culture being 
conducted on scientific principles : the success of practical men 
is due to the discovery and cariying out of these principles, 
although they may be ignorant of them, and may not recog- 
nize them as such. The idea that the farmer requires nothing 
but practice and experience to ensure success, is as erroneous 
as to suppose the school teacher requires no knowledge of 
arithmetic or grammar. Not a blade of grass can be made to 
grow without perfect confoimity to the laws of nature, — and 
still the farmer arrogates to himself the credit of success in an 
operation, the philosophy of which he neither does, nor desires 
to understand. 

The failures of practical men in attempting to apply some 
new principle, are o-vving to want of knowledge and skill in 
combining science with practice, — and not to any disci-epancy 



14 INTRODUCTION. 

in facts. It must be admitted that many of the processes of 
successful farming are not yet explained, — and many things, 
true in theory, are not, as yet, demonstrated in practice, but 
this does not justify the conclusion that nature is not entirely 
consistent with herself Men have been too much disposed to 
consider certain phenomena as "mysterious and past finding 
out," and thus have ended their investigations. 

But the time has arriYed when the application of science is 
the only means of any great success in agriculture ; and those 
who reject this Hght must be content to plod their way 
through Kfe Hke one groping in darkness, — be considered as 
wanting in intelligence and enterprise, — to accomplish but 
little and barely subsist, — wliile the scientific farmer reaps 
abundant harvests. However strong the prejudice may be 
against what is absurdly called "book farming," — the old 
empyrical system cannot, in a country where the population is 
dense, the soil becoming exhausted, and manures scarce, 
maintain a successful competition with one which is conducted 
upon scientific principles. 

No art or profession presents more points of contact with the 
various branches of natural science than that of agriculture ; 
and in no pursuit is education regarded as of less importance. 
While in all the learned professions and many mechanical 
arts, education is considered indispensible, — the farmer Avhose 
knowledge consists of reading, writing, and a few empyrical 
dogmas of his ancestors, is supposed to be abundantly quali- 
fied for his caUing. Trained and educated in all the old and 
established practices of his fathers, he is sceptical upon all 
that is written, and slow to adopt any new improvement in 
practice. 

An ancient philosopher being asked what things were most 
proper for boys to learn, replied, — "Those things which they 
intend to practice when they become men." Now inasmuch 
as ao-riculture involves the same branches of knowleds;e as 



INTRODUCTION. 15 

most other arts and professions, it follows of necessity that the 
farmer requires the same education and discipline of mind as 
those do who practice law, medicine, engineering, and the 
mechanical arts. 

Agriculture should not be looked upon as the end of hfe, — 
but only as a means of securing the necessary food for subsis- 
tence : this, as wtII as all other pursuits, should be adopted 
with the view of enabling 'men not only to improve and 
beautify the earth, but to cultivate the moral, intellectual and 
social powers, and to fulfil according to their capacity, their 
proper station among their fellow men. It should not tend to 
make men mere machines, who toil for the sole purpose of 
gratifying •groveUing and depraved appetites: but it should 
elevate and refine to the highest degree of perfection, all the 
better faculties of our nature. 

A large part of the farming comm.unity already recognize 
the utihty of the natural sciences in the cultivation of the soil. 

Some elementary books have been written which have 
been favorably received by the farming pubUc. Among 
the natural sciences. Geology has received more attention than 
any other among this class of men. The connection of this 
science with agriculture is so apparent to every one who 
learns but the rudiments of it, that it needs only to be intro- 
duced, (in treatises which are plain and well arranged,) to be 
studied and apphed in practice. It teaches the origin and 
nature of all the various soils and rocks, and all great physical 
changes which are taking place from natural causes on the 
earth, and beneath its surface. 

Botany is also of much importance : and indeed the agTicul- 
turist and horticultuiist are the only persons to whom the 
study and practical apphcation of its principles are indispen- 
sible. It teaches the characters, habits and localities of nearly 
one hundred thousand different species of plants: it treats 



16 INTRODUCTION. 



^ 



also of their pkysiology, and explains many of the most 
interesting processes of vegetation. 

Chemistry is the key which unlocks the great laboratory of 
nature, and shows us how she performs her complicated 
processes, and produces all her wonderful phenomena. 

Meteorology mvestigates all the facts and phenomena per- 
taining to weather, climate, seasons, temperature, storms, lati- 
tude, altitude, wands, &c. 

Zoology treats of the habits, localities, depredations and 
uses of all the objects of the animal kingdom. Comparative 
anatomy and physiology constitute a branch of zoology which 
treats of the form, structure, functions, differences and pecu- 
liarities of all the organs of animal bodies. It is the basis of 
all knowledge relative to breeding, rearing, feeding, and 
curino; the diseases of animals. 

Natural Philosophy treats of the properties and dynamic 
forces of light, air, water, and the mechanical powers, and 
their application to machinery and other practical purposes of 
life. Besides these, many other branches of knowledge are 
indispensible to the education of the accomplished agricultu- 
rist. The study of astronomy, geography, architecture, politi- 
cal economy, algebra, geognetry, — a knowledge of the lan- 
guages, general hterature, and the fine arts to some extent, — 
and in fact we might say, a complete collegiate course, belongs 
as much to the farmer as to the professional man. 

But the means by which this amount of preparatory educa- 
tion is to be attained by farmers' sons, are not yet provided. 
Various plans for ag-ricultural schools have been proposed, 
none of which have been successful in this countiy. Where 
such schools have been established and endowed -with compe- 
tent instructors, libraiy and apparatus, the number of pupils 
have been a mere fraction of the young men who were 
destined for agricultural pursuits. While a few are ambitious 
of high attainments, the great mass are indifferent, or preju- 



INTRODUCTION. 1 7 

diced against what they suppose to be only an innovation. In 
this way the schools fail for want of patronage, and young 
men are deprived of their education for want of schools. 

But if we are not yet prepared to sustain agricultural 
schools, some_ other plan may be available. The teachers of 
common schools may be educated in scientific agriculture, so 
as to be able to instruct all such pupils as are designed for 
this pursuit, in at least the elements of the most necessary 
branches. In this way the germs of science will be planted 
and a taste excited, which will lead ultimately to a thorough 
and systematic course of study. 

This plan, though hmited and imperfect in its operation, has 
the advan^^ge of g'iving to boys the early impressions, and a 
preference for those studies, which, if proper books are acces- 
sible, may be pursued in connection Avith practice in after hfe. 
A plan has been proposed for securing the agricultural educa- 
tion of teachers, w^hich is to estabhsh a professorship of agri- 
cultural science in the State Normal School. By this means 
teachers could be educated, who would be competent to teach 
the science to the extent required in the schools of farming 
communities. 

Every farm should be considered a chemical laboratory, 
and every farmer a practical chemist and philosopher : fanning 
would then be honorable and lucrative. Education would 
give to the cultivator of the soil that dignified confidence and 
polish which he has a right to possess, — and which he now 
too often ridicules or envies in men in other pursuits. No 
reason exists why rural pursuits should alienate their votaries 
from the rest of mankind, and give rise to those jealousies and 
suspicions with which th^ look upon men of other occupa- 
tions, or fin the mind with that doooed arrog-ance which is 
always the offspring of ignorance. 

The profits of productive farming would, when conducted 
scientifically, enable the farmer to accumulate wealth, and 



18 fllli^B INTRODUCTION. 

enjoy all the comforts and luxuries of refined life. Every 
community could be made up of the best society, — every 
family could have its fine library and its accomphshed sons 
and daughters: farmers' sons need not leave the favorite 
pursuit of their fathers, and go into the learned professions, 
from the erroneous conclusion that they were more honorable 
or profitable. Farmers' daughters need not despise the 
delightful and healthful employments of the dair)% the 
kitchen, or the loom, — and seek elevation in the miserable 
pursuits and fashions of the city. 

Nothing conduces more to the elevation and refinement of 
the mind than the study of nature ; the man who holds fre- 
quent communion with nature, and studies and obeys her 
laws, is always made a better and happier man. 

The more we explore the mysteries of nature, the more are 
we humbled with the reflection, that to our finite view, only a 
small part of her works are comprehensible. And when, after 
years of patient toil, we fancy we have learned most of her 
laws, we still find the great Author has only opened to our 
view new vistas to more extensive and unexplored fields of 
knowledge. It has been truly said, that he who can teach men 
to think, deserves a monument. 

"Nature is alwaj^s perfect and unvarying, but man's 
knowledge is progressive; consequently in every advance he 
arrives nearer the truth, yet is far from knoAving all nature 
and her laws as he is from infinity. Exact knowledge consists 
in those things which can be seen and demonstrated, — while 
in all knowledge of inference there is progression. Opinions, 
which are often the result of imperfect knowledge, are hable 
to change, and the mind is never advanced by adopting the 
opinions of others; for by that means man is never made a 
thinking being, but rests upon authority. In all sciences, the 
acquisition of new truths exhibits in a new fight, the beautiful 
and harmonious operation of the laws of nature." 



INTRODUCTION. 19 

Besides the benefit of mental discipline derived from the 
study of nature, for which agriculture opens as wide a field 
as any other pursuit, the charms of rural hfe are unalloyed 
by the reflection of ill-gotten gain, and uncontaminated by 
immoral influences. The farmer has no occasion to renew 
with remorse, a hfe of injustice to his fellow men, or mourn 
the loss of fortunes accumulated by an occupation almost 
necessarily dishonest — The lawyer looks upon liis briefs pre- 
pared for unjust causes, the ph3'sician upon the emaciated 
forms of his patients, and the speculator upon the wealth 
amassed from the ruined fortunes of others, with the humilia- 
ting consciousness that they have not, in all cases^ returned an 
equivalent^ for what they have received. But the cultivator 
of the soil may pursue his calhng with the cheering reflection, 
that an all bounteous Providence has rewarded his eftorts, and 
through him bestowed means of happiness upon his fellow 
men. 

The reminiscences of rural life and scenes are always 
pleasant : who would not wish to return to the bounding and 
joyous days of youth, which were spent among woodland 
scenes, green fields, along the river's shore, on the sunny hill's 
side, or in the silence of the cool ravine, where every object 
lent enchantment to the scene, afforded pleasure without 
alloy, and prepared the mind for the admiration of nature and 
study of her laws in maturer years? What haunts so sacred, 
what objects so hnked to our affections, as those associated 
with rural life in childhood. Who that appreciates the 
quietude and smiling plenty, the balmy air and variegated 
landscape of the country, — would not prefer it to the crowded 
noisy streets, the pestiferous atmosphere and demoralizing 
influences of the city? It is in the country alone that man 
enjoys the beauties of nature, as she spreads them out before 
him in all their wild luxuriance, or as she patiently smiles 
beneath the impro\ing hand of cultivation. 



20 INTRODUCTION. 

Agriculture is an honorable, a delightful and a glorious 
pursuit : the first man who hved on earth was an agriculturist^ 
— and agTiculture must exist till the last man leaves it 

But all labor is honorable: the Great First Cause 
works, — nature works, — and every man who enjoys her 
fruits, ought to hold it honorable to work. ^Mien shall the 
glorious time arrive that intelligence and true pliilanthropy 
shall annihilate the selfish distinction which pride has made 
between labour and idleness ? May that auspicious day soon 
dawn when the worthless distinction between mental and 
physical labour shall cease to exist, which separates man from 
his fellow man, — and all the tenants of earth meet as equal 
sovereigns of our common inheritance. 



NATURAL SCIENCE. 



Naturai, Science embraces all the objects of the material 
creation, from the minutest insect, plant, or particle of dust, to 
the most «vast of the celestial spheres. This great field of 
knowledge is divided into Natural Philosophy and Natural 
History. Natural Philosophy elucidates the laws which gov- 
ern the phenomena of the material world, — and is divided 
into Chemistry and Physics. Chemistry treats of phenomena 
which depend upon a change in the constitution of bodies: 
Physics treats of the dynamical properties and phenomena of 
bodies, which do not depend on a change in constitution or 
elements. 

Natural History treats of the character and properties of 
individual objects: these are divided into three great natural 
groups, called kingdoms, — viz. the animal, the vegetable, and 
the mineral kingdom. Natural objects are distinguished also 
into two gTeat classes, termed animate-organic and inanimate- 
anorganic. All the individuals of each of the primary divi- 
mons, are again divided or grouped into Classes, Orders, Ge- 
iicra, and Species. 

The di%adino- line between oro-anic life and inanimate mat- 
ter, is not well defined ; between the lowest form of organic 
life and the most perfect and symmetrical crystal of the mine- 



22 NATURAL SCIENCE. 

ral kingdom, however, the distance must be almost immeasura- 
bly great. Passive motion or change is the peculiar attribute 
of inorganic matter : it can neither enjoy life, nor be subject 
to death: but life and organization are inseparable, — to this 
combination, birth and death are the necessary and invariable 
terms of existence. 



PART I. 



CHEMISTHY 



CHAPTER I. 

The science of Chemistiy has for its object, the investigation 
of the properties of all elementary and compound substances, 
tlieir relations and combinations, the agencies by which their 
changes are effected, and the laws which govern them. The 
basis on which this science rests, is facts and experiment; and 
as it is purely a demonstrative physical science, no hypotheti- 
cal or speculative views can be practically made of any ser- 
vice to its advancement and application. 

Every change which takes place in the elementary consti- 
tution of matter in the universe, whether efiected by natural 
causes or by the operations of art, involves a fixed chemical 
law, and is due to chemical action. 

Chemistry consists of two distinct branches, viz. Analysis 
and Synthesis. Analysis consists in decomposing a compound 
body and separating its elements. Synthesis consists in uni- 
ting simple bodies so as to form a compound substance. The 
forces which preside over and cause all chemical changes, are, 
attraction, light, caloric, electricity, and magnetism. The rela- 
tive importance of these several forces cannot be exactly esti- 
mated in the present state of the science : the question as to 



24 SCIENTIFIC AGRICULTURE. 

their individual nature, or identity with electricity, remains 
unsettled. 

The science of chemistry, which has achieved greater tri- 
umphs over matter, and conferred more practical knowledge 
of nature upon ci\ilized man than all other sciences com- 
bined, — has gradually grown out of the superstitious art of 
Alchemy. *' 

Modern chemistry, instead of alluring its votaries into a 
fruitless search after the " philosopher's stone " or the " univer- 
sal solvent," crowns their investigations rih results which tend 
to the advancement of ciAilization, and the increase of human 
comforts and happiness. Its objects are not Hmited to the 
stud s of abstract laws alone ; — but also to the improvement of 
the useful arts, the cure of disease, the production and prepa- 
ration of food, the study of the laws of organic hfe, and finally 
to every thing affecting our physical relations to the material 
universe. 



PROPERTIES OF BODIES. 

CAPILLARITY. 

Capillarity is the force by which small tubes and porous 
substances absorb and raise fluids above the surface of that in 
which they are immersed. This force depends upon the cohe- 
sion of the molecules, or ultimate atoms of the fluid for each 
other, and the attraction of the soHd body for those of the 
fluid. If we dip the end of a small tube open at both ex- 
tremities, into a fluid, it will be observed to rise slowly above 
the surface of the surrounding mass : if one corner of a sponge 
be dipped into water and allowed to remain, it will by Adrtuc 
of its capillarity in a little time be saturated ; the water hav- 
ing been raised by this force against the antagonizing force of 
gravity. • 



CHEMISTRY. 25 



COHESION". 



Coliesion is the force by wliich tlie particles of a homogene- 
ous body are held together and resist separation. Caloric is 
the opposing or antagonizing force of cohesion. " The three 
different forms -which matter assumes, — viz. sohd, liquid, and 
gaseous, — are determmed by the degree of the cohesive force 
existing among the elementary particles." This force is great, 
est in solids, less in fluids, and least in gases. In gases this 
force is negative or absent, tiie particles having a tendency to 
repel each other. The globular form of the drops of Hquids 
depends upon this force. 

It is easy to conceive, that if cohesion were to be suspended, 
all solids us well as fluids would assume the gaseous form ; 
the repulsive tendency being then uncontrolled. This can be 
eflected to a certain extent by means of heat: heat overcomes 
the cohesive power of sohds, and changes them to liquids : but 
when the heat is removed, they are again changed to solids by 
cohesion, — as in the case of melted iron: bodies naturally 
liquid, as water and mercury, are volatilized by heat, and as- 
sume the gaseous form. Tlie cohesive f<>rce acts at insensible 
distances. 

DIVISIBILITV. 

Matter is capable of being divided int(i.^inconceivably small 
particles. We have, liowevjr, no means of determining the 
question of its infinite divisibility. We can easily imagine that 
the minutest particle which can be produced by mechanical 
means, must still have extension, form, and weight, and would 
be divisible, (had we instruments sufliciently delicate,) into 
other particles, and these again into others, and so on until 
they totally disappear from the limit of our conceptions. 
But we cannot, by any process whatever, annihilate or destroy 
the least particle of matter. 

The particles of hydrogen gas, Avhich is itself fourteen times 
lighter than common air, would individually present an idea 



26 SCIENTIFIC AGRICULTURE, 

almost inconceivable. And still this gas is material, and must 
be made up of an aggregate of particles. A single grain of 
gold used in gilding silver wire, is made to cover a surface of 
1400 square inches, and still the gold upon the millionth of a 
square inch when examined by the microscope, is distinctly 
visible. A square inch of gold leaf may be divided into one 
billion and four hundred millions of paVticles, and still retain 
all the characters and color of a large mass. 

Chemical action may be supposed to carry the process of 
division to a much hioher attenuation than mechanical means. 

o 

A single drop of solution of indigo colors 1000 cubic inches of 
water, and yet this coloring matter is an aggregate of distinct 
particles. The fineness of particles has an important effect 
on the chemical action of one body upon another. Perhaps a 
more definite idea may be given by the following example. 
The author had the pleasure of examining Anth Professor 
Dewey's improved microscope, some fossil infiisorioe, which 
were so small that they appeared like perfectly impalpable 
powder, and not the least gritty between the teeth. These 
minute particles of dust, when subject to the greatest magni- 
fying power of the instrument, proved to be the shells of in- 
fusoriae resembling in shape the soio-hiig and trilobite, and ap- 
parently from three to four inches in length and one inch in 
width. And still, minute as they were, they must have had, 
when li\ing, all the organs and machinery of animals of large 
size. 

GRAVITY. 

The term gra\dty, in natural philosophy, signifies weight : it 
is that force or attraction in nature which causes all bodies to 
move towards the earth when not prevented by some other 
force. The gravitating force of a body is in proportion to the 
quantity of matter which it contains. The velocity and force 
of gravity increase in falling bodies, in proportion as they ap- 
proach the earth. Bodies of the same bulk, do not always pos- 



CHEMISTRY, 27 

sess the same gTavity or weight, owing to diflference in density : 
thus, lead weighs about twelve times as much as cork, bulk for 
bulk, — that is, it contains twelve times as much matter, — and 
hence it has twelve times the o-ravitatino- force. 

What this grantating force is, has not been determined ; all 
we know in relation to it is, its effects. Sjyenjic gravity, de- 
notes the weight of any body, compared with some other body 
of equal bulk, which is taken as a standard and is reckoned at 
unity. Water is taken as the standard of specific gra\ity for 
solids and fluids, while atmospheric air is the standard from 
which the weight of the g-ases is estimated. 

DENSITY. 

By density is understood, the compactness of bodies, or the 
number of ultimate particles contained in a given bulk : bodies 
which contain the most particles are most dense, — that is, their 
particles are in the closest proximity to each other. Rarity, or 
porosity is the opposite quaUty of density. Density does not 
depend upon the peculiar kind of matter of which a bod}^ is 
composed, but only upon the proximity of its particles. This 
is apparent, from the fact that the lava ejected from volcanoes, 
if cooled on the surface of the earth, produces a stone suffi- 
ciently hght and porous to float upon water, — while, if cooled 
under great pressure at a distance below the surface, it forms 
a dense heavy rock hke granite. 

ELASTICITY. 

Elasticity is the property in bodies, which causes them to 
resume their original form and bulk, after being bent, com- 
pressed, or condensed. Most sohd and hard bodies possess 
this quality in some degree: glass, ice, ivory, <fec., are elastic 
solids: india-rubber is an exceedingly elastic body, — while wet 
clay is entirely destitute of tliis property. The gases are far 
the most elastic of all bodies. 



I 



28 SCIENTIFIC AGKICULTURE. 

TENACITY. • 

By tenacity, we understand the degree of force or cohesion 
with which the particles of a body are held together, — in other 
words, tenacity means toughness. Some substances, as some 
of the metals, are extremely tenacious, while others want this 
quahty almost totally. The tenacity of the metals varies great- 
ly, — cast steel being tlie most tenacious of them all, while lead 
is the least so. The tenacity of the woods varies, as does also 
that of soils : clay soil is tenacious, while sand soil is destitute 
of this property. 

CHEMICAL ATTRACTION, OR AFFINITY. 

Tliis is a peculiar power in bodies, which disposes them to 
imite with other bodies and form compounds. It is the power 
by which chemical phenomena are produced: it is different 
from cohesion ajad ail other forces in nature: it acts with 
various degrees of energy in different elementary bodies, — 
showing a preference for some, and refusing to act on others 
at all. Chemical affinity is influenced by many other agents, 
as heat, electricity, gravity, cohesion, moisture, elasticity, and 
light. An affinity originally vreak, may by some of these 
agencies be made strong, while an affinity originally strong 
may be rendered weak, or destroyed altogether. 

When common salt is thrown in Avater, it unites with it, 
(dissolves,) by means of a Aveak affinity or chemical attraction, 
— but if oil be thrown into water, it does not unite with it, 
because it has no affinit}^ for it. Some substances unite in all 
proportions, as for example, vinegar and water; while others 
unite only in definite and fixed proportions, as sulphuric acid 
and fime, &c. When two substances of opposite natures are 
broug'ht together, as vinegar and pearlash, they readily unite, 
by means of shn^^Ie affinity/, and form a third substance dif- 
ferent from either of the other two. If now a third substance 
be added, which has a stronger affinity for one of these two 
than they have for each other, the two first separate, or are 



CHEMISTRY. 29 

decomposed, and one of them goes to unite with the new 
substance, and form a compound, by means of elective affinity. 

Two bodies which have no affinity for each other, may 
sometimes be made to unite by means of a third: thus, oil and 
water will not unite alone, — but by the medium of the alkali 
potash, which has an affinity for both, they unite and form the 
well known compound, soap.* Chemical union is usually 
attended with the evolution of heat. Some substances unite 
without any apparent action, while others have an affinity so 
strong that union takes place with an explosion. Chemical 
affinity manifests itself in a more complex form under the 
name of dmible elective affinity. 

A case of double elective affinity is seen in the action of 
sulphate of zinc upon acetate of lead. Their respective for- 
mulae may be stated thus: 

... f 1 1 \ Acetic Acid, 

Acetate of lead, j Oxide of IciJd. ' 

o 1 1 A r- • ( Sulphuric acid, 

Sulphate oi zmc, - - - - j q .-Jj r , • 

When mixed together in solution an entire interchange of 

elements ensues : their formulae will then stand thus : 

Acetic acid, ) k 4. j. c • 

^ . 1 c • i Acetate 01 zmc. 

Oxide 01 zmc, \ 

Oxide of lead, ) c^ ^ \. j. c ^ i 

Sulphuric acids " " " " Sulphate of lead. 

Thus, two compounds are destroyed and two new ones 
formed at the same time, by the operation of double elective 
affinity, and they are held together by a stronger attraction 
than the first two were. 

When nitrate of ammonia and carbonate of potash are 
mixed together in solution, a double decomposition and union 

* This example is taken from Comstock's Chemistry on account of 
its plainness ; but is nevertheless not strictly true, as the idea of an 
intermediate substance is now abandoned by chemists. The truth is, 
that the alkali and oil unite and form soap, which it itself dissolved in 
the water. 



3. Potash. } Carbonate 

4. Carbonic Acid, i" of Potask. 



30 ^SCIENTIFIC AGRICULTURE. 

take place : the potash leaves the carbonic acid to go to the 
nitric acid, and the nitric acid leaves the ammonia to go to the 
potash, — the carbonic acid and ammonia, finding themselves 
deserted and ..alone, unite and form carbonate of ammonia. 
Thus nitrate of ammonia and carbonate of potash are decom- 
posed, and nitrate of potash and carbonate of ammonia formed. 
This may be more clearly shown by arranging tlie four ele- 
ments thus : 

Nitrate of (1. Nitric Acid, 
Ammonia. \ 2. Ammonia. 

This change of elements took place because a stronger 
afiinity existed between 1 and 3, than between 1 and 2. 
These compounds might again be decomposed by others, hav- 
ing affinities sufficiently powerful to overcome that which holds 
them toQ-etlier. In order that bodies may be united by affin- 
ity, they must possess different chemical properties : thus acids 
and alkalies are chemically opposed, and are consequently 
drawn together, while they rarely, if ever, unite with each 
other. " We miglit [says Dr. Fownes] define chemical afiiinity 
to be a force by which new substances are generated." 

LAY.'S OF COMBINATIOX. 

Tl^e elements of chemical compounds are generally limited 
to fixed and invariable proportions on both sides. It is this 
constancy of proportions alone, which gives to chemistry its 
title to the character of an exact science : for had all bodies 
the property of combining in every possible proportion under 
every variety of circumstances, no definite or certain knowledge 
could be obtained in relation to the constitution, properties, or 
chemical uses of bodies: experiments would give results so 
diii'erent and variable at different times, and under various 
circumstances, that chemists would long since have abandon€)d 
the science in despair. 

The elements of a given chemical compound are always in 



CHEMISTRY. 3 1 

the same proportions: thus, green oxide of iron is composed 
of 27 parts, by weight, of iron, and 8 parts of oxygen: com- 
mon salt is a compound of 23 parts sodium and 35 parts 
chlorine; and these are the smallest proportions in which 
those elements can be made to unite. When two elements 
unite in more than one proportion on either side, the additional 
proportions are just double, triple, quadruple, izc, or 1 to ^ — 
that is, 2 to 3, — 3 to 5, — the amount of the first : that is, they 
increase in exact multiple proportions. To illustrate this 
principle, we may allude to the five compounds of oxygen and 
nitrogen. 

Protoxide of nitrogen consists of — 

Oxygen, 8 

10 

" 24 

32 

" 40 

It will be seen that while the nitrogen remains the same, tliC 
oxygen increases by multiples of 8, which is its equivalent 
number. The nitrogen, although willing to unite with several 
whole proportions of oxygen, would reject a quarter or a half 
of an equivalent, and not unite with it: so, in the preparation 
of any compound, if an excess of either element be used, it is 
not combined, but left alone in its original state. 

The equivalent or combining number of a body is that which 
represents the smallest quantity in which it is known to com- 
bine with other bodies. The representative number of a com- 
pound is, the sum of the combining equivalents of its compo- 
nents. Combining proportions are reckoned by weight and 
by volume ; in these two estimations of course different equi- 
valent numbers are used. 



Kitrogcn, 


14.06 


Dent oxide " 


14.00 


Ilijponitrons acid " 


14.06 


Nitrous acid " 


14.06 


Nitric acid " 


14.00 



CHAPTER 11. 



LIGHT. 



In order to understand the relations of liglit to vegetation, a 
short description of its properties is necessary. There are two 
theories respecting the nature of hght: one supposes it to be 
particles of luminous matter, emitted or thrown off by luminous 
bodies. The other supposes the existence of a substance 
called ethevy which pervades all nature, and is put into a 
■\ibrating or wave-like motion by all luminous bodies. 

Rays of light proceed in straight hues from luminous bodies, 
unless interrupted by some intervening medium. Light moves 
with the astonishing velocity of 200,000 miles in a second of 
time. When a ray of light falls on a plane surface, it is 
disposed of in one of three ways : when the plane is rough and 
black, the ray is all absorbed : when it is pohshed, the ray is 
partly absorbed and partly reflected : when the plane is trans- 
parent, as glass or water, it may be partly absorbed, partly 
transmitted, and partly reflected. The law of reflection of light 
is the same as that of sound : when a ray of hght falls obhquely 
on a reflecting surface, it is reflected in the same angle as the 
one in which it approached the surface ; thus the angles of 
reflection and incidence are equal. 

When a ray of light passes from a rarer to a denser medium, 
it is refracted, or turned out of its course : when it passes from 
a rare to a denser medium, as from the air into water, it is 



t'llEMlSTRi'. 



33 



bent towards the perpendicular : Avhcn it passes from a dense 
to a rarer medium, it is turned from the perpendicular. 

Light is a compound of seven colors, viz : violet, indigo, blue, 
green, yellow, orange and red. The colors can be separated 
by a triangular piece of glass, called a prism : they possess 
different degrees of refrangibihty, as will be seen by the 
fioure. 

Fig. 1. Solar Spectrum. 



Violet 
Indigo - 
Blue - 
(ircen - 
Yellow 
Orange 
Red - 




[This cut shows the solar spectrum in the order of its seven colors: 
the violet appears most, and the red least, refracted.] 

There are also heating rcujs, which attend the luminous 
ones : the calorific, or heating powers of the red rays, are the 
greatest: these powers diminish in the order of the spectrum, 
from the red to the violet, which possesses the least of all. 
Light is a powerful decomposing agent : many chemical com- 
pounds, as the salts of silver, are decomposed by the agency 
of lio-ht alone. The influence of lioht on veo-etation is very 
important, and will be noticed hereafter. The process of 
taking photographic and Daguerreotype pictures, depends upon 
the action of lioht on a sensitive metallic surface. 

o 

There are several sources of light : the great source of light 

which produces the day to our earth, is the sun, — the moon's 

light is only a reflected light which it receives from the sun. 

The combustion of bodies is another source of lio-ht: another 

form of light is called phosphoresence, which is emitted by 

certain bodies, as phosphorus, decayed wood, putrid flesh, 

2* 



34 SCIENTIFIC AGRICULTURE. 

certain gasses, &c. : this is a feeble light, and is only visible in 
darkness. 

CALORIC. 

Caloric is the substance or agent which is thrown off by 
heated or burning bodies, and which produces the sensation 
of heat: in common language it is the word used to express 
both the cause and the effect. This agent possesses no appre- 
ciable weio-ht. Althouo'h it must be substance, or material 
in its nature, — still a body when highly heated or charged 
with caloric, is not sensibly heavier than w^hen cold. 

Caloric appears to exist in all bodies.' Heat and cold are 
only relative terms ; when a body is so cold as to produce the 
sensation of coldness to our touch, we call it cold; on the 
contrary, when it produces the sensation of warmth, we call it 
warm, — although the absolute temperature may be the same 
in both cases. Caloric always tends to seeh an equilibrium: 
that is, it constantly passes from the hotter to the colder 
bodies: if a piece of ice at 32° be carried into an atmosphere 
where the temperature is 60° below 32°, it ^^dll, in changing 
its temperature to that of the surrounding air, give oft' 60° of 
heat : this illustration is sufficient to prove that the ice really 
contains heat. 

The expansive power of heat is another property which 
involves many important facts ; when caloric enters a body, it 
is supposed that a mutual repulsion of its particles takes place, 
so as to partially overcome their cohesive power, and render 
the body less dense. All bodies expand by heat, — the degree 
of this expansion, however, differs widely in different bodies. 
The expansibility of fluids is greater than that of sohds, with 
equal degrees of heat. 

All gases expand nearly equally with the same degrees of 
heat : this is not the case, however, with the solids and liquids. 
Some bodies are much better conductors of caloric than others : 



CHEMISTRY. 35 

dense bodies are generally the best conductors of caloric: 
the metals are better conductors than wood or glass; porous 
bodies conduct with less facihty than dense ones. Snow is 
porous, and therefore a poor conductor of caloric, — this is why 
the o-round freezes less when covered with snow, than when it 
is naked. 

The different conducting power of bodies is illustrated by a 
famihar example: on a cold winter morning we find the 
hearthstone intensely cold to the feet, while tlie woolen carpet 
is w^arm : now^ as they are both exposed to the same tempera- 
ture, the different sensation produced must depend on the differ- 
ent conducting power of the two bodies, the one conducting 
off the heat of the body so rapidly as to produce the feeUng 
of coldness, and the other conducting but very slightly. 

By S2)ecific caloric is understood, that quantity which is 
peculiar to each body : when one body is found to possess a 
greater amount of caloric than another of equal weight, it is 
said to possess a greater capacity for caloric. The reason 
why different substances possess different capacities for caloric, 
is not precisely known. Bodies less dense appear generally 
to possess the greatest capacity for caloric, — while those more 
dense possess the least. Hydrogen gas, the hghtest of all 
known bodies, is said to possess this capacity in the greatest 
degree. 

When a piece of cold iron is hammered for a few seconds 
it becomes hot: when sulphuric acid is mixed with a Hquid 
less heavy and dense, as water or alcohol, the mixture becomes 
hot ; when ice melts and becomes water, it absorbs heat The 
fteat which is absorbed in the last case, is called latent heat. 
This water in passing back to ice, gives off its latent caloric, 
which now becomes sensible. 

All heated bodies are constantly emitting or throwing off 
caloric ; this is called radiant caloric, — because it is radiated 
in all directions like the rays of light. Tliis .effect is not 



36 SCIENTIFIC AGRICULTURE. 

produced by the gradual conduction of caloric by tlie air, 
because the same effect takes place in a vacuum, and in a 
direction opposite to the wind. When rays of heat fall upon 
any body, they are, like the rays of hght, either absorbed, 
reflected, or transmitted. Highly pohshed substances reflect 
the heat, — while rough surfaces absorb it. The angles of 
incidence and reflection are equal in radiant caloric, as well as 
in light and sound. The color of bodies has an important 
influence on their radiating power : dark colors radiate better 
than light ones. 

The transmission of heat through the air takes place 
without any obstruction, as is the case with light; but with 
respect to other transparent media it is different. " If a para- 
bolic or concave mirror be taken, and its axis directed towards 
the sun, the rays of both heat and hght will be reflected to 
the focus, which will exhibit a temperature suflEiciently high to 
fuse a piece of metal, or fire a combustible body. If a plate 
of glass be now placed between the mirror and the sun, the 
effect ^\ill be but little diminished. Now let the same experi- 
ment be made with the heat and Hght of a common fire ; botli 
will be concentrated by reflection as before, — but on inter- 
posing the glass the heating effect of the focus will be reduced 
to almost nothing, while the light will not have undergone 
perceptible diminution." 

" Thus the rays of heat coming from the sun traverse glass 
with great facility, which is not the case with those emanating 
from an ordinary red hot body." Rays of heat are not 
transmitted equally through different bodies of equal trans- 
parency; for example, of 100 rays falUng on a crystal of rock 
salt, 8 were intert-epted : of the same number, glass inter- 
cepted 61, and alum 91. Color also varies the power of 
bodies to transmit heating rays. Black and opake bo'dies stop 
the rays completely. Rays of heat from different sources 
differ in theii* properties: those proceeding from red hot 



CHEMISTRY. 37 

copper and fluor spar, differ from those from an oil lamp or 
the sun. Cold is merely a negative condition depending on 
the absence of heat. 

There are several sources of caloric, of wliich the sun is the 
principal, and compared with which all others are insignificant. 
The sun radiates heating as well as luminous rays, Avhich 
reach the earth, and are partly absorbed and partly reflected. 
The combustion of bodies is another source, — electricity, gal- 
vanism, friction, condensation, animal vital action, and chemical 
action, are all sources of caloric. The earth is supposed to 
contain in its interior a vast amount of heat. The relations 
of heat to the growth of vegetation are important, and will bo 
noticed in^anotlier place. 

ELECTRICITY. 

Electricity is a fluid or principle pervading all nature, so far 
as we know. The first full investigation of this extensive and 
interesting branch of science was made by Dr. Franklin ; and 
although it is only a few years since, yet it has become iden- 
tified with almost every branch of physical science, and has 
already had an immense influence on the moral and social, 
as well as commercial condition of the ci%'ilized world. We 
still know httle of the nature of electricity ; although many of 
its properties and eff"ects are somewhat well understood, still 
all investigation and discovery has only tended to render its 
true nature and phenomena more mysterious, and its origin 
more questionable. We see its efi'ects, but what it is, or 
whence it originates, we know not. 

But for the sake of convenience, philosophers have applied 
certain terms to its peculiar properties : these terms in some 
cases indicMe particular effects and conditions, and in others 
they may be said to be httle more than names for our 
ignorance. Electricity is supposed to be a fluid which exists 
in two opposite states, viz : positive and negative. The terms 



38 SCIENTIFIC AGRICULTURE. 

vitreous and resinous have also been used to designate these 
two states. Vitreous electricity is supposed to be developed 
from viti'eous substances, as glass: resinous electricity is de- 
veloped from resinous substances: this distinction is only 
hypothetical. 

The simplest manner of exciting or producing electricity is 
by rubbing a piece of amber or seahng wax on dry cloth, 
when it will be found capable of attracting light bodies, such 
as feathers, bits of thread, paper, &c. The body so affected is 
called an electric, and is said to be in a state of electrical 
excitation. The sealino' wax or amber in this case is in the 
positive state, or is positively electrified, while the feather or 
other substance attracted to it is in the negative state, or is 
negatively electrified. It is impossible to develop one of these 
states or phenomena without at the same time developing* the 
other also. After adhering to the electrical body for a few 
seconds it will fall off, it being charged with electricity and in 
the positive state like the electric: if the electric be excited 
again, and the feather presented to it, it will be strongly 
repelled "and tend to fly off — this is called electrical re2^ulsion. 
Hence the rule : bodies similarly electrified repel, — bodies 
oppositely electrified attract each other: or, like repels like 
and attracts its opposite. 

The passage of the electric spark is instantaneous : it appears 
also to be confined to the surface of bodies in its passage. 
Bodies wliich allow electricity to pass over them are called 
conductors : these are non-electrics, — that is, they cannot be 
excited by friction so as to produce electricity : on the con- 
trary, those bodies which can be electrically excited will not 
conduct the fluid; so that non-conductors are electrics, and 
non-electrics are conductors. 

The electric spark fires gaseous mixtures, and is capable of 
producing intense heat: electricity also decomposes solutions 
of metallic oxides and salts. Some fishes, as the torpedo and 



CnEMISTRT. 39 

electrical eel, possess an electrical apparatus within their 
bodies, which is capable of producing severe shocks upon 
other animals ; and this is done, too, at the will of the fish. It 
has been satisfactorily settled by Prof. Matteucci, that electri- 
city has nothing to do with the action of the nervous system 
of animals, and that hfe and all the \dtal functions are not 
dependent upon it for their existence and action. Electricity 
gives polarity to iron, and is "supposed to be the cause cf, or 
identical with maonetism. 

The polarity of the earth is supposed to depend upon the 
passage of electrical currents around it. Electricity is desig- 
nated according to its different states, by the terms statical 
and dynamical. Statical electricity treats of the properties of 
the fluid *at rest or in a state of equihbrium. Dynamical 
electricity treats of the fluid in motion, or as it displays its 
phenomena while under experiment The upper regions of 
the atmosphere are generally in a positive state; in cloudy 
weather, the distribution of the fluid is disturbed, and this 
gives rise to the phenomena of thunder and lightning. Gal- 
vanism, as well as magnetism, is supposed to be . identical 
with, or a modification of, electricity. 

Electricity is developed in various ways, by diflerent kinds 
of apparatus which cannot be described in this place. All the 
forms of electricity are apphed to useful purposes, to con- 
siderable extent, in the arts and sciences. It remains an 
unsettled problem as yet, whether electricity in any form can 
be made available to the gTOwth of vegetation: its efficacy, 
also, in the healing art, is not as much rehed upon as in 
former years ; this, like all newly discovered remedial agents, 
has had its day of glory, and has, probably, by means of 
correct obseiTation and careful experiment, fallen to about its 
proper standard. 

Note. — Tiie term Pyrogen has been proposed instead of Electricity: 
the term signifies generator of heat or fii'e. 



CHAPTER III. 



GENERAL PROPERTISS OF GASES. 

Gas is an elastic fluid or air, formerly, but not now, supposed 
to be produced by the union of some body with caloric : most 
gases are inappreciable by any of the senses, except that of 
feeling, having neither taste, color nor odor. Some have a spe- 
cific gravity greater, and others less, than common or atmos- 
pheric air. Several gases have been liquified by the conjoined 
action of cold and pressure : several have also been solidified 
by the conjoined action of intense cold and the pressm'e of 
from two to fifty atmospheres. The product of this experiment 
is in most cases an exceedingly transparent crystaline sub- 
stance. Gases, like liquids, have but a slight power of con- 
ducting caloric : their conducting power is so slight as to be 
imperceptible, and they are therefore called non-conductors 
of caloric. Elasticity is that property in gases which causes 
their molecules, by a kind of repulsive force, to separate from 
each other and occupy a greater space : the density of a given 
proportion of gas, is always in proportion to its tension, — or, 
*' the volume of one and the same mass of gas is inversely as 
its expansive force." Heat increases the expansive force of 
gases. 

All gases possess a certain amount of specific caloric, — the 
precise quantity which they respectively contain has not been 
determined. Gases exist throughout nature, and may be 



CHEMISTRY. 41 

produced by artificial means. Some of them are capable of 
being respired, without injury to health, while others cannot, 
without producing deleterious or fatal effects. Some are, in 
common language, supporters of combustion, while others are 
not Those gases only which are necessary to be known in 
their relations to agriculture, wiU be described in this work. 

OXYGEN ITS PROPERTIES AND RELATIONS. 

Oxygen is an in^dsible, transparent fluid, without taste or 
odor; respirable and necessary to organic hfe, with a specific 
gravity of 1.26, air being 1. It has the most extensive 
affinity of* all known substances. It combines with metals, 
forming oxides and acids : it combines also with other gases, 
and is an important element in water and the atmosphere : it 
is usually called a supporter of combustion, — it exists in great 
abundance in nature, and may be obtained by chemical process 
from several substances, — most easily, perhaps, from black 
oxide of manganese. It is said that nearly one-third of the 
weio-ht of all the sohd matter of the globe consists of this 
gas. The combustion of all fires depends on the presence of 
oxygen, — a hghted taper burns with greatly increased bril- 
liancy in pure oxygen gas. 

No plant can vegetate without it, although no plant will 
long survive after being placed in this gas alone. No animal 
can respire for a single moment without oxygen, but when 
immersed in a jar of it, the vital processes are all increased 
until fever succeeds, and the animal dies. " According to 
Dr. Henry, 100 volumes of water absorb only 3^ of oxygen." 
The combining number of oxygen is 8. 

HYDROGEN ITS PROPERTIES AND RELATIONS. 

Hydrogen gas is the Hghtest of all known substances, being 
fourteen times lighter than common air, — destitute of taste, 
color or odor : it is combustible, but not a supporter of com- 



42 SCIENTIFIC AGRICULTURE. 

bustion; it is incapable of sustaining animal life, tboiigb it 
is destitute of poisonous properties, — an animal dies when 
immersed in it for want of oxygen, — the deatb results from 
its negative condition, ratber than from any positive injury 
wbicli is sustained by breathing the gas. It exists in nature 
in less abundance than carbon or oxygen, and is not known to 
occur in a free or uncombined state. It forms a small part of 
all animal and veo-etable substances, and constitutes one-ninth 
part of the weight of water : it does not occur in combination 
with any of the mineral masses of the globe, except coal, — and 
this is itself of vegetable origin. This gas burns with a pale 
yellow flame, — its combustion is attended by the formation of 
water. 

Plants do not grow in this gas, but gradually wither and 
die. Its specific gravity is 0.0687: 100 gallons of water 
absorb l-g- gallons of this gas. It is the gas used for inflating 
balloons. Hydrogen is readily obtained by the action of sul- 
phuric acid on zinc or iron. It is necessary to the growth of 
vegetation, but not in a free or uncombined state. The com- 
bining number of hydrogen is 1. 

CARBON ITS PROPERTIES AND RELATIONS. 

Carbon exists in a pure and crystaline form in the diamond ; 
graphite, or black lead, and common charcoal, are examples of 
carbon of impure varieties. It constitutes a large proportion 
of all animal and vegetable substances : nearly all plants in a, 
dried state, contain from 40 to 50 per cent, by weight, of 
carbon. This substance is of great importance in the art of 
culture, on account of its power of absorbing large quantities 
of the gases and vapors of the atmosphere, — this is especially 
true of charcoal, or carbon in a hght and porous form. Char- 
coal is used for filtering impure water, which it cleanses from 
decayed animal or vegetable substances, and coloring matters 
which are held in solution : it is used also in clarifying sjTups 
and oils: it has the power of absorbing noxious vapors and 



CHEMISTRY. 43 

gases, wluch. result from the decomposition of animal and 
vegetable matters, and of preventing or retarding the decay 
of all oro-anic substances. 

o 

The gases and moisture which are arrested and retained by- 
carbon in the soil, are again readily yielded up to the roots of 
plants, during the process of growth. Several important ends 
are subserved by carbon in the soil : it purifies impure air and 
water, which would not nourish plants, but on the contrary 
prove destructive to their tender germs and roots : it absorbs 
gases from the air as before stated ; prevents putrefaction (and 
acidity to some extent,) in the soil, and is itself an indispen- 
sible element in vegetation. 

Carhonic acid is a gas or air, wliicli results from the com- 
bustion of charcoal, — when charcoal is burned, it nearly all 
disappears in the form of gas, leaving only a small residue of 
ash behind. Carbonic-acid-gas is heavier than common air, 
colorless, invisible, having an agreeable pungent taste and 
odor, but cannot be respired without poisonous eflfects resulting 
from it. Carbonic acid may be obtained for experiment from 
white marble, which is a carbonate of hme, or from common 
limestone. The combining number of carbon is 6. 

It is neither combustible nor a supporter of combustion, — a 
lighted taper dipt into a jar of this gas is instantly extin- 
guished ; — it often exists in deep wells, mines, caverns and pits, 
and proves fatal to those who enter them, — the precaution 
should therefore always be taken to let down a lighted candle, 
which will determine the presence or absence of the gas. It is 
this gas also which proves so deleterious in ill ventilated rooms 
heated by coal fires. It is formed during the combustion of 
all wood, coal and oil fires, — it is generated by the respiration 
of animals and the growth and decay of vegetation: it is 
produced also, together with alcohol, during the fermentation 
of sugar. It is evolved in vast quantities from the ground in 
volcanic countries, and exists in combination with metallic 



44 SCIENTIFIC AGRICULTURE. 

oxides in the earth: these compounds are called corbonates, 
the most important of which is carbonate of hme. This gas 
has an acid reaction : water dissolves its own volume of it, and 
forms an agreeable sparkling solution: it is this gas which 
escapes during the effervescence of soda water and various 
kinds of beer. 

It is apparent that the excessive accumulation of so poi- 
sonous a gas must prove destructive to all animal and vegeta- 
ble hfe, if some means were not provided by which it could be 
removed as fast as it is generated by natural causes : growing- 
vegetables, although they could not hve in this gas alone, 
require a constant supply of it as an element of food, — and 
this is just sufficient to preserve a wonderful balance in this 
respect throughout all nature* 

According to Liebig, a healthy man expires from his lungs 
6 ounces a day, or 100 pounds a year, of carbon: a horse, or 
cow, expires six times this amount, — or 600 pounds a year. 
Now if the crops of an acre of land require 2 tons of carbon in 
a year, (which is Johnston's estimate,) a farm of 25 acres , 
would require, if all cultivated, 50 tons of carbon. If the 
family of the farm be reckoned at 5 adults, and the stock at 2 
horses, 5 cattle, 40 sheep, 5 hogs, including the poultry, the 
amount of carbon they would all expire would not be far from 
10 tons in a year. They would then supply from this source 
alone one-fifth of all the carbon requisite to grow the crops of 
the farm. 

Coal which is dug from the earth and burned as fuel, adds 
to the carbon of the atmosphere a new portion, which had 
been buried in the earth, and consequently lost to vegetation 
for many centuries. The coal consumed annually in Great 
Britain, contains 14 milHons of tons of carbon, which would 
supply this element to the crops of twenty-eight milHons of 
acres. — [Johnston.] Decay of vegetation, when extensive, as 
in the peat bogs of Europe, the jungles of India, and the 



CHEMISTRY. 45 

tropical forests of Africa and South America, furnishes im- 
measurable quantities of carbon. 

The final result of this eremacausis, (slow combustion,) or 
slow decay, is the same as that of ordinary combustion: the 
immediate result, however, is different : decay furnishes much 
less carbon in proportion to the matter consumed than com- 
bustion; decay produces, also, light carburetted hydrogen, 
which combustion does not. The latter gas is changed by the 
electricity of the air to carbonic acid and water. 

The evolution of carbon from volcanoes, and fissures in the 
earth in volcanic regions, is immense. In the ancient volcanic 
reoion of Eifel, on the bank of the Rhine, an annual evolution 
takes plac^, according to Bischoff, of 27,000 tons of carbon. 
Some carbon is absorbed by the waters of seas and oceans, 
which is not, as far as we know, restored to the atmosphere. 
Vegetable matters carried away by water, deposited and em- 
bedded in beds of sand and clay, are thus prevented from 
decaying, and their carbon is consequently lost. These are 
two sources of loss of carbon: and althouo-h the balance 
between its production and consumption is nearly equal, still, 
according to Prof Johnston, there is supposed to be a slight, 
permanent loss to the entire mass of our atmosphere. 

NITROGEN ITS PROPERTIES AND RELATIONS. 

Nitrogen is widely diffused through nature, constituting 
nearly four-fifths of the atmosphere, and existing in many 
vegetable, and most animal substances. It is destitute of 
color, taste or odor, and is a httle lighter than common air ; it 
is incapable of supporting combustion or animal life, — but, like 
hydrogen, it has no positively poisonous properties. Water 
absorbs it in very small quantity : it is in fact distinguished for 
negative properties, — ^the reason why it does not sustain com- 
bustion and animal life, appears to be merely the absence of 
oxygen. Its use in the atmosphere seems to be only to dilute 



46 SCIENTIFIC AGRICULTURE. 

the oxygen sufficiently to render it fit for respiration. Nitro- 
gen has a stronger affinity for hydrogen than for any other 
body. 

Nitrogen combines with oxygen and forms acids and oxides. 
Its combining number is 14. Nitrogen may be obtained by 
burning phosphorus under a bell glass over water. It does 
not enter into the composition of any of the mineral con- 
stituents of the earth's crust, except coal, which is of vegetable 
origin. Nitrogen forms an important part in the growth of 
both animals and plants. 



GASEOUS COMPOUNDS. 



WATER ITS PROPERTIES AND RELATIONS. 

Pure water is transparent, colorless, tasteless, and inodor- 
ous : it is a compound of the gases oxygen and hydrogen, in 
the proportion of 8 parts of the former to 1 of the latter, by 
weight, — or by volume, 1 of oxygen to 2 of hydrogen. It 
boils, under ordinary circumstances, at 212° and freezes at 
32° Fah.: its greatest density is at about 40°, — at 212°, it 
takes the form of vapor or steam, and is thus increased to 
1700 times its former bulk, and is about two-fifths lighter than 
common air, — it consequently rises and becomes diffused 
through the air. 

Water evaporates at all temperatures above freezing: it is 
"780 times hea\ier than common air, — a cubic foot weighs six- 



CHEMISTRY. 47 

ty-two and a half pounds. It is the standard of specific graviiy 
for all bodies, — its number in tliis respect is unity or 1. 

The purest water, except that which has been distilled, falls 
from the clouds in the form of rain and snow at the close of a 
shower; all other natural waters contain various soluble and 
insoluble gaseous, mineral and organic matters, — among wliich 
are, carbonic acid, carbonate of lime, ammonia, salts of iron, 
soda, iodine, bromine, magnesia, silica, sulphur, and others. 
Water possesses the most extensive solvent power of all known 
liquids : it absorbs gases from the air to a considerable amount : 
these are again expelled by boiling, and are altered in their 
proportions from those which constitute the atmosphere. 

Water qjiixes Tsith, or dissolves all hquids except those of an 
oily nature : it dissolves also most salts, many gums, coloring- 
matters, and slowly dissolves many rocks and earths: water 
has a wide range of affinities for animal, vegetable and miue- 
ral elements, which it exercises without being itself decom- 
posed. It is the most universally diffused through the three 
kingdoms of nature, of any substance : it enters largely into 
the composition of living animal bodies, and constitutes, ac- 
cording to Johnston, half the weight of all green or newly 
gathered vegetables which are cultivated for the use of man. 

Without water, neither animals nor plants could exist, (with 
their present organization,) the earth would become a scorched 
and sterile waste : many compounds resulting from chemical 
affinities wliich require the presence of water, would be un- 
known : the varieties of climate which now exist would also 
to a oTeat extent be unknown. Water in its relations to veo-e- 
table life, and also its meteorological influences, will be more 
particularly discussed in a subsequent part of this book. 

THE ATMOSPHEEE ITS PROPERTIES AND RELATIONS. 

The atmosphere which we breathe is an immense ocean of 
gaseous fluid ; the depth of this ocean is about 45 miles, at 



48 SCIENTIFIC AGRICULTURE. 

the bottom of which we live, — or rather, it extends about 45 
niiles above the surface of the earth, which it entirely sur- 
rounds. It is composed of the two gases, oxygen and nitro- 
gen, in volume, in the proportions of about 21 of the former 
to 79 of the latter in 100. It contains also, according to 
Sausseur, o^'oo of its bulk of carbonic acid. According to Lie- 
big, the atmosphere contains also at all times, a minute quan- 
tity of ammonia. 

The quantity of this gas is greater in cities than in the coim- 
try, slightly less in the air over the seas and great lakes, — it 
is less over a wet than a dry soil, and by day than by night. 
The air is imbued mth watery vapor which varies in different 
climates : it holds in suspension, traces of various animal and 
veo-etable matters and ammonia. Heat and electricity also 
exist more or less at all times in the atmosphere. Air diffuses 
itself everywhere, penetrates the minutest recesses of every 
porous body, and presses vrith the almost incredible weight of 
1 5 pounds to every square inch of the earth's surface : it is 
transparent, colorless, invisible, elastic, tasteless and inodorous. 
The two essential elements of the atmosphere, viz : oxygen and 
nitrooen, are not, accordino- to Dr. Kane and others, in a state 
of chemical union, but only a mixture. 

The specific gravity of air is about 780 times less than that 
of water; 100 cubic inches weigh about 31 grains. A column 
of air 45 miles high just balances a column of Avater of the 
same diameter, 33 feet high, or a column of mercury 29 
inches high : hence water cannot be raised in a pump on the 
principle of atmospheric pressure, more than about 33 feet, — 
hence also the mercury in the barometer tube is about 29 
inches high. The air expands and becomes less dense by 
heat ; hence warm air always rises, and cold air descends : the 
composition of the air is everywhere nearly uniform, — its com- 
plete and beautiful adaptation to the wants of animal and 
vegetable life will be more apparent the more we become 



CHEMISTRY. 49 



acquainted witli its nature and laws : -svitliout it no animal or 
plant could exist for a single da}^ Its relations to vegetation 
more especially, "will be descrfbed hereafter. 



CARBONIC OXIDE. 



Carbonic oxide is a colorless, inodorous gas, composed of 
one equivalent of carbon, itiijited to one of oxygen: it extin- 
guishes a hghted taper, takes %e at the same time itself, and 
burns with a pale blue flame-, forming carbonic acid. It is 
lighter than common air, nearly insoluble in water, and does 
not support animal life. It is produced, together "svith car- 
bonic acid, by the combustion* of coal fires. " It is not known 
to occur Jn nature, or to minister directly to the growth of 
plants." 

OXALIC ACID. 

Tliis is another compound of carbon and oxygen, in the 
proportions of two of the former to three of the latter. It is 
found in the interior of many plants, as the sorrel, rhubarb, 
bistort, gentian, chick pea, and several lichens : it is not known 
to contribute to their growth, but appears to be the result of a 
gaseous combustion consequent upon their growth. It is 
found combined with potash and lime in the form of salts 
called oxalate of potash and lime : it is one of the most impor- 
tant of the oro-anic bodies. 

Crystalized oxalic acid is, in transparent bodies, intensely 
sour, and very poisonous. This acid is not found in the soil, 
nor in the waters which reach the roots of plants : the simple 
process by which it is elaborated in the interior of plants will 
be described hereafter. Oxahc acid neutralizes alkalies per- 
fectly, and forms several important salts. There exists a rela- 
tion between carbonic acid, carbonic oxide and oxalic acid, 
which vv'ill be described under tlic head of vegetable physi- 

olooT. rt 



50 SCIENTIFIC AGRICULTURE. 



LIGHT CARBURETTED HYDROGEN. 



This is a liglit, inflammable gas, whicli is formed by the 
decomposition of organic substances at a high temperature : in 
warm weather it may be seen rising in bubbles from marshy 
places and stagnant pools, where vegetiibles are in process of 
decomposition. This gas is colorless, destitute of taste or odor, 
about half the weight of common air: a lighted taper is 
extinguished by it, while the gas ignites and burns with a pale 
yellow flame : animals immersed in this gas cease to breathe 
almost instantly. This is the gas which exists in marshes 
under the name of marsh gas, — and also in coal mines under 
the name of fire clamp: violent explosions sometimes took 
place in coal mines by the ignition of this gas mixed with 
oxygen, from the miners' lamps, previous to the invention of 
the safety lamp by Dr. Davy. It consists of one equivalent 
of carbon and two of hydrogen. 

This gas, together with carbonic acid, is given off during 
the fermentation of compost, and all large collections of vege- 
table matter. "It is supposed, [says Johnston,] by many, to 
minister to the nourishment of plants: it is, however, very 
sparingly soluble in water, so that in a state of solution, it 
cannot enter largely into the pores of the roots, even though it 
be abundantly present in the soil:" it probably exists in the 
well manured soils ; " but the extent to which it really acts as 
food to living vegetables is entirely unknown." 

NITRIC ACID ITS PROPERTIES AND RELATIONS. 

Nitric acid is a compound of one part nitrogen and five of 
oxygen: liquid nitric acid, when pure, is colorless, intensely 
sour and corrosive, heavier than water, and boils at 187° Fah- 
renheit. If exposed to the air, it gives off white fumes with 
the disengagement of part of its oxygen, becomes yellow, and 
is converted into nitrous acid. 



CIIEMISTRr. 51 

** True nitric acid [says Dr. Kane] has never been isolated ; 
that substance generally spoken of as nitric acid, is a compound 
of it v.'ith water ; it is a nitrate of water, or, as it is popularly 
termed, liquid nitric acid, or aquafortis." This acid decom- 
poses all organic substances rapidl}^,. neutralizes the alkalies, 
and oxidizes the metals, for which /t has a strong affinity. 

This acid is not found in nature in an uncombined state ; but 
it occurs in combination Avith soda, lime and potash, in the 
form of nitrates, in many tropical countries. In the West 
Indies, vast quantities of nitrate of potash (salt petre) are 
formed by nature: in Chili and Peru, immense beds of nitrate 
of soda are also found. The origin of these salts is as follows: 
rain water, particularly that which falls during a thunder 
shower, contains nitrate of ammonia, when the water comes in 
contact with the potash, soda and lime of the soil, — having a 
stronger affinity for them than for the ammonia, is again set free 
and escapes into the air. Tliese salts are soluble in water, and 
are important agents in promoting the gTOwth of cultivated 
plants. 

Nitre is found in the wells of towns, but has not yet been 
found in the water of wells in the countiy at a distance from 
the towns. — Liebig. 

AMMONIA ITS PROPERTIES AND RELATIONS. 

Ammonia is a colorless gas, having a strong, pungent odor 
and alkaline taste : it is composed of one proportion of nitro- 
gen and three of hydrogen: its equivalent number then is 17. 
It is slightly combustible, but does not support combustion. 
*'Ammonia is rapidly absorbed by water, which takes up 780 
times its volume at 32°:" this is called water of ammonia, or 
sjnrits of hartshorn, — it has a specific graAity about one-tenth 
loss than water, and boils at 120°. In its power of neutrali- 
zing acids, it ranks next to hme, being a powerful base: it 
forms, with the metallic salts and with acids, many compounds. 



52 SCIENTIFIC AGRTCULTURE. 

Ammoniaeal gas does not support respiration, — animals are 
speedily suffocated by it, and living plants confined in it soon 
•wither and die. It is absorbed largelj^ by porous bodies, such 
as charcoal, burnt brick, burnt clay, &c, — charcoal is said to 
absorb 95 times its own bulk. 

Ammonia is sufficiently caustiii to destroy both animal and 
vegetable substances. It is remarkable that the two gases 
■which form ammonia, having neither taste nor odor when 
separate,, produce when united in certain proportions, a gas so 
intensely strong, pungent, and acrid. Ammonia being only 
about three-fifths the weight of common air, it rises and 
mingles with the air when it is set free, unless it is retained 
by some substance with vv'hich it will unite and form a solid 
substance not volatile. The salts of ammonia are easily soluble 
in water. 

Ammonia exists in considerable abundance in nature, — it is 
almost universally diffused, but does not enter as a constituent 
into any of the mineral masses of the earth's crust. It is found 
mostly in a state of combination with acids, in the form of 
nitrate, muriate and carbonate of ammonia. According to 
Liebig, ammonia exists in small quantities in all the oxides of 
iron. It is evolved largely by the decay of animal and vege- 
table matters, and does not remain long in a free state in 
the air, but combines with acid vapors which it meets in the 
atmosphere, and forms other compounds. 

The salts of ammonia are decomposed by lime, magnesia, 
potash and soda, and the ammonia is set free in the gaseous 
state : the ease with which compounds of ammonia are decom- 
posed, constitutes one of its most valuable properties, and 
renders it peculiarly adapted to the various offices it performs 
in the processes of vegetation. In the air, the soil, or the 
interior of plants, it is easily decomposed by electricity and the 
alkaline bases before named. 

" The hydrogen it contciins'in so large quantit}^ [says Prof 



CHKMISTRT. 53 

Johnston,] is ready to separate itself from the nitrogen in the 
interior of the plant, and, in concert with the other organic 
elements introduced by the roots or the leaves, to aid in pro- 
ducing the different solid bodies of which the several parts of 
plants are made up. The nitrogen also becomes fixed in the 
colored petals of the flowers, in the seeds, and in other parts, 
of which it appears to constitute a necessar}^ ingredient, passes 
off in the form of new compounds, in the insensible perspira- 
tion or odoriferous exhalations of the plant, — or returning with 
the downward circulation, is thrown off by the root into the 
soil from which it was originally derived." The transforma- 
tions whicli actually take place in the interior of plants, is not 
yet perfectly understood, although many of them can be 
clearly explained. The agency of ammonia and its various 
compounds, in the promotion of vegetation, is both powerful 
and important, — and will be explained more fully in a subse- 
quent chapter, as will also its formation and sources. 

Ammonia as already stated exists in the atmosphere, and is, 
according to Liebig, the only source of the nitrogen of plants : 
as it has not been proved that plants can decompose the atmos 
phere and appropriate its nitrogen, we may at least suppose 
they obtain it from some other source. " Science is at present 
ignorant of any compound of nitrogen besides ammonia, capa- 
ble of yielding nitrogen to wild plants on all parts of the 
earth's surface. IS'o other such compound of nitrogen has been 
indicated, or even hypothetically supposed to exist and desigv 
nated by a name, in the case of cultivated plants ; and there- 
fore until a second source of nitrogen is discovered, we must, 
in science, view ammonia as the only source." — [Liebig. 



CHAPTER IV". 



ELEMENTARY BODIES. 

Elementary or simple bodies, are those -which consist of 3 
single substance, and cannot be decomposed, or reduced to a 
more simple form. They are such as have hitherto resisted 
all attempts at decomposing them; but still, new methods of 
analysis may yet enable the chemist to prove them to be of a 
compound nature, — and indeed this has already been the case 
with some which were formerly considered elementary. These 
simple bodies are about sixty in number, so far as yet known ; 
but chemical analysis will doubtless make us acquainted Avith 
others. Several attempts at classification of these bodies have 
been made; but none, as yet, has been on all accounts unob- 
jectionable. 

One division is, into metallic and non-metallic substances: 
this division, although entirely arbitrary and less philosophical 
than some othei-s, is still the most convenient, and sufficiently 
explicit for our present pui-pose. It is the one adopted by 
Doct. Fownes. 

Non-Metallic Elements. 

Chlorine, Silicon, 

Iodine, Boron, 

Bromine, Sulphur, 

riourin©. Selenium. 



Oxvjxen, 
Hydrogen, 
IS^itrogen, 
Cai'bon, 



CHEMISTRY. 



55 



Elements of Intermediate Characters 



Phosphorus, 



Telhirium. 



Arsenic, 
Metals. 

Antimony, 

Chromium, 

Vanadium, 

Tungsten, 

Rhodium, 

Iridium, 

Osmium, 

Gold, 

-4kmiinum, 

Gkicinum, 

Zirconium, 

Thorium, 

Cadmium, 

Copper, 

Iron, 

Manganese, 

Lithium, 

Sodium, 

Pelopium, 

Kiobium, 

Molybdenum, 

Columbium, 

Titanium, 
These sixty simple elements combine with each other in 
such manner as to form the innumerable compounds which 
make up the whole animal, vegetable, and mineral kingdoms. 
So far as we know, all ponderable bodies in the universe are 
only the varied compounds of these few substances. The 
imponderable agents, light, caloric, electricity, galvanism, and 
magnetism, and the vital principle, are not well understood in 
their natures and composition ; so that nothing can be predi- 



Uranium, 

Cerium, 
Lantanum, 

Platinum, 

Palladium, 

Yttrium, 

Bismuth, 

Tin, 

Mercur}'-, 

Silver, 

Lead, 

Barium, 

Strontium, 

Calcium, 

Magnesium, 

Zinc, 

Nickel, 

Cobalt, 

Potassium, 

Ruthenium, 

Erbium, 

Terbium. 



56 SCIENTIFIC AGRICULTURE. 

cated as to tlieir relation in composition to the simple bodies. 
Such, only, of these bodies will be described, as are necessary 
to be known in their relations to agricultural science. 

ACIDS. 

Acids are chemical compounds which are capable of uniting 
in different proportions with alkaUes, to form a third class 
called salts : by this union the properties of both the acids and 
alkalies are destroyed, or neutraUzed. Most acids have a sour 
taste, — there are, however, some exceptions: they change 
vegetable blues to red; they are electro-negative, and there- 
fore have a strong affinity for the electro-positive compounds, 
such as alkalies, alkahne earths, and oxides. Nearly all of 
them contain oxygen; when the oxygen is not present, it is 
replaced by hydrogen: they are therefore called by some 
writers, oxacids and hydracids. 

Acids are divided again into mineral and vegetable; the 
mineral are nitric, sulphuric, muriatic, &c. : the vegetable acids 
are very numerous, — acetic, citric, and tartaric, are examples. 
Most vegetable acids contain both oxygen and hydrogen. The 
mineral a«ids are heavier than water, exceedingly caustic and 
corrosive, — destroying both animal and vegetable textures. 
Some acids are in a fluid, and others in a dry, sohd, or crys- 
taline form. They unite with water in all proportions. They 
absorb water from the atmosphere, if exposed, and become 
weaker in strength, diminished in weight, and increased in 
bulk. 

ALKALIES. 

Alkalies are a class of bodies possessing properties opposite 
to those of acids, having a strong affinity for, and uniting with 
them in different proportions, to form salts, as before stated. 
They are incombustible, caustic, and acrid, v.eiy soluble in 
water, and change vegetable blues and red to green, and yellow 
to brown,— in fact they destroy or change the vegetable colors 



CHEMISTRY. 57 

generally. They are divided into fixed and volatile, — the 
fixed alkalies are potash and soda: these do not evaporate, hke 
ammonia, which is therefore called a volatile alkali. They 
have a sharp, pungent taste, destitute of acidity, and, "with the 
exception of ammonia, have but little odor. They unite with 
the oils and fats, and form the well known compound, soap. 
There is also a class of compounds called alkaline earths, as 
lime, barytes, magnesia, and strontium. The alkalies and alka- 
line earths are electro-positive in their affinities. 

SALTS. 

Scflfs constitute a numerous class of compounds, which 
result from the chemical union of acids and alkahes. They 
are of three kinds, viz : acid, basic, and neutral. 

Acid salts contain an excess of acid ; most of them are not 
really acid salts, but double salts, of which one base is water; 
bi-carbonate of potash is an example. — [Kane.] The sub- 
stance which unites with an acid to form a salt, is called a 
base. 

Basic salts are those in which there is more than one 
equivalent of base for one of acid, as in sulphate and nitrate 
of copper. 

Neutral salts do not manifest either acid or alkaline proper- 
ties on vegetable colors, — they have neither an acid nor an 
alkaline taste, and generally consist of one equivalent of acid 
and one of base. 

Double salts are formed by the union of two simple salts; 

in general both salts contain the same acid, but different bases. 

Salts usually crystalize in regular determinate forms; some 

being in prisms or crystals, having three, four, five, six, 

&c. sides, and many angles. Most salts contain some water 

in a loose state of combination : this is called their tvater of 

crystalization. This water evaporates from some salts, and 

they become a dry powder, — such are called efflorescent salts'. 

3* 



58 SCIENTIFIC AGRICULTURE. 

others absorb more water from the atmosphere, and are dis« 
solved in it, — these are called deliquescent salts. 

Salts may effloresce or deliquesce without destroying their 
pecuHar quahties or the chemical union between the acid and 
base. Salts dissolved by water, again crystalize when the 
w^ater is evaporated. The ciystals of some salts are very 
small, as in epsom salts, — ^in others they are large, as in chro- 
mate of potash. 

ORGANIC ELEMENTS OF PLANTS. 

Organic bodies possess a much greater complexity of com- 
position than substances of mineral origin. The organic 
bodies are distinguished from the inorganic by the nature of 
their elements: the products of the vegetable kingdom surpass 1 1 
in number and variety those of the mineral, — but still those of 
the former consist almost exclusively of six elements, viz : car- 
bon, oxygen, hydrogen, nitrogen, sulphur, and phosphorus : of 
these six, carbon alone exists in all bodies of both animal and 
vegetable origin. Sulphur and phosphorus are met with but 
seldom: iodine and bromine exist in marine plants and 
sponges; besides, tliese plants contain in most cases, irony 
silicon, calcium, potassium, magnesium, manganese, and some- 
times Jliforine. These are called the ultimate elements of 
plants, — because they are the final result of anal3^sis, and 
cannot themselves be reduced to a more simple form, or sepa- 
rated into ether elements. 

These combine in such a manner as to form the various 
substances, such as starch, gum, sugar, and an almost endless 
variety of others found in plants. These latter are called 
organic 2>t'oducts, or immediate or proximate elements, because 
they are more easily separated, and obtained without a rigid 
analysis. As a general rule, bodies most complex in their 
number of elements and simplicity of equivalent relations, are 
the weakest, and least capable of resisting those disturbing 



CHEMISTRY. 59 

forces vrliich tend to produce decomposition, or transformation 
of their elements. Substances of different properties, but 
identical in composition, are called isomeric bodies. 

These bodies, although containing the same ultimate ele- 
ments, m-iy be as ■widely different in their chemical relations 
as bodies which have no elements in common. Oil of turpen- 
tine and oil of citron are isomeric compounds, — each being- 
composed of carbon 5 — hydrogen 4. 

LIGXINE. 

The proper wood of plants, when separated by chemical 
means from all soluble substances, is called liynine. It is 
composed of carbon, hydrogen, and oxygen, — these are its 
constant elements, whether it be obtained from the porous 
willow, dense box\yood, or the fibres of hnen and cotton. The 
hydrogen and oxygen exist in the same proportions as in 
water; so that lignine is apparently only carbon and water: 
but distillation does not prove this to be the case. 

Pure lignine is white : it undergoes no decomposition in dry 
air, or under water which contains no air; but by the joint 
action of heat and air it undergoes changes which produce 
another series of compounds, very different from itself Woody 
fibre is arrano-ed in cells and tubes: the walls of these cells 
and tubes are composed of cellular woody fibre, and covered 
by a scjid substance called incrusting matter. It is difficult to 
separate the two, so as to determine by analysis the precise 
difference in their composition. It is evident that wood}^ fibre 
constitutes the great mass of all forest trees, and also of the 
dried stalks and roots of most plants. 

STARCH. 

Starch is probably the most abundant product of vegeta- 
tion, mill the exception of woody fibre. It is obtained from 
the flower of all the grains, many roots, the pith and seeds of 
many other plants. Starch is obtained in the form of a fine 



60 SCIENTIFIC AGKICULtURE. 

powder, consisting of rounded, shining wMte particles. Tliey 
are tasteless and inodorous, and Avlien kept dry undergo no 
change in any length of time. Starch is insoluble in cold 
water or alcohol, but dissolves readily in hot water, and forms 
a jelly. Starch, hke lignine, is composed of carbon, hydrogen 
and oxygen. Starch is a delicate test for the presence of 
iodine. 

Ai'rowroof, sago, ta2noca, inuline, and lickenine, are varieties 
of starch. It is frequently deposited among the woody fibres 
and in the inner bark of trees, as the willow, beech and pine. 
This is the reason, [says Prof. Johnston,] that the branch of a 
willow takes root so readily, and also, that the bark of trees is 
used in some countries as food. 

GUM. 

Gum arable is a familiar example of this class of substances ; 
the gum from peach and plumb trees is similar in constitution. 
Pure gum is light colored, having a sweetish taste, destitute of 
odor, insoluble in alcohol, soluble in water, with which it forms 
an adhesive mucilage. Gum is composed of carbon, hydrogen | 
and oxygen: it exists in the seeds and other parts of many 
plants. Arahine, carasine, hassorine, dextrine, and traga- 
canthine are all varieties of gum: this, as well as starch, is 
highly nutricious as food. 

SUGAR* 

Sugar exists in many plants, — but is obtained principally 
from sugar cane, sugar maple, and beet root. Pure sugar is 
in large transparent crystals, having a pure sweet taste, desti- 
tute of odor, soluble in water, highly nutricious. Its constit- 
uent elements are carbon, hydrogen and oxygen. Graiie 
sugar, sugar of milk, and sugar of mushrooms, are all va- 
rieties. A 



I 



CHEMISTRY. 61 

MUTUAL RELATIONS OF LIGNINE, STARCH, GUM AND SUGAR. 

It is a remarkable fact, that these four substances, though 
possessing properties so entirely different, are composed of the 
same elements in the same proportions. This fact, so e\ident 
to the analytical chemist, is still httle more comprehensible to 
him, after his most profound investigations, than to the most 
unlearned. And, although we can readily separate the ele- 
ments of these bodies, we cannot combine the same elements 
so as to form any one of them. The formulaa below show 
their constitution. 

Woody fibre is composed of C. 12, H. 10, 0. 10. 

Starch " " " C. 12, H. 10, 0. 10. ' 

Gum " " " C. 12, H. 10. O. 10. 

Cane sugar " " " C. 12, H. 10. O. 10. 
These four substances are capable of being transformed one 
into another, as woody fibre into starch, starch into sugar, gum 
into sugar, ifec, as will be hereafter described. 

GLUTEN. 

Gluten exists in the flour of wheat, rye, barley and oats, 
from which it ma}^ be obtained by washing the paste or dough 
for a long time in water. It is a soft, tenacious, elastic, grayish 
substance, with very little taste or odor. It is nearly insoluble 
in water, but easily dissolved by alcohol, acids and alkalies : 
when moist gluten is dried at 212°, it becomes a semi-trans- 
parent, yellowish, brittle mass, resembling glue. Wheat con- 
tains more gluten than any of the other grains : it contains, 
according to its quality, from 8 to 35 per cent. Gluten is 
highly nutritious: it is composed of carbon, hj'-drogen, oxygen, 
and nitroo'en. 

o 

ALBUMEN. 

Albumen is a gelantinous, colorless substance, without taste 
\ or smell, dissolved by acids and alkalies, but insoluble in 



62 SCIENTIFIC AGRICULTURE. 

alcoliol and water. Albumen resembles tlie white of eggs, 
which is animal albumen ; it abounds in the juices of many 
plants, as cabbage, turnips, &c. : its composition is identical 
with that of gluten, wliich is as follows : 

Carbon, 54.76 
Hydrogen, 7.06 
Oxygen, 20.06 
Nitrogen, 18.12 



100 

When exposed to air and moisture it undergoes decomposi- 
tion, which is attended by the formation of vinegar and ammo- 
nia. It possesses highly nutrient properties. 

WAX. 

Wax is found in many plants: beeswax may be taken as 
the type of this class of bodies. It is insoluble in water or 
cold alcohol, but dissolved by boiling alcohol, which separates 
it into two proximate principles, viz: cerine and myricine. 
Beeswax melts at 144*^, and when freed from its yellow 
coloring matter, has a white, crystaline appearance. Cerine, 
boiled with a solution of potash, forms soap. Wax is supposed 
to be derived from the oils of plants. 

RESIN. 

Resin is obtained from the pitch of various of the coniferous 
family, such as the pine, hemlock, fir, (kc. Resin is highly 
inflammable, insoluble in water, but readily dissolved by 
alcohol and essential oils: the principal resins are, common 
rosin, copal, mastic and elemi. Common rosin is what remains 
after the distillation of pitch to obtain spirits of turpentine. 

CAMPHOR. 

Camplior is a gum-like, white, brittle, semi-transparent sub- 
stance, having a strong peculiar odor and an acrid bitter taste. 



CHEMISTRY. 63 

It exists in several plants, but is found in most abundance in 
the camphor tree. It is highl}^ inflammable, and resembles in 
some respects the resins : it is nearly insoluble in water, but 
dissolved by alcohol and oils. 

CAOUTCHOUC. 

Caoutchouc, or India Rubber, is the product of several 
trees in tropical countries, from which it exudes in the form of 
a milky juice which hardens by contact with the air. It is 
insoluble in water or alcohol, and dissolves but imperfectly in 
ether ; its proper solvent is volatile oils : oil of turpentine dis- 
solves it, but it dries imperfectly afterwards. At a tempera- 
ture a little above that of boihng water it melts, and never 
resumes its elasticity : in its properties, it possesses considerable 
resemblance to the resins : it may be converted into a volatile 
oil by distillation. 

FIXED OILS. 

0^75 are divided into two classes, viz: Jixed and volatile: 
the former are capable of being distilled without decomposi- 
tion, — the latter are not. The animal and vegetable oils agree 
in their properties very nearly in eveiy respect. The fixed 
oils are obtained by pressure, from the seeds of various plants, 
as the castor bean, flax seed, (Src. 

They have httle taste or odor, are lighter than water, con- 
geal at a lower temperature, and require a higher heat than 
that of boiling water to evaporate them. They are highly 
nutritious, and combine with soda to form soap; by contact 
with air they become rancid and gumm}^ : they are all inso- 
luble in water, and, with the exception of castor oil, but 
slightly so in alcohol: they dissolve easily in ether and the 
volatile oils. 

VOLATILE OILS. 

Volatile or essential oils are numerous in the veo-etable 
kingdom, and give to plants their pecidiar odors; they are 



64 SCIENTIFIC AGRICULTURE. 



« 



obtained by distillation. Most of tliem are lighter than water, 
highly combustible, and dissolve in alcohol to form essences: 
when pure they are colorless, and evaporate from paper 
without leaving a greasy stain, as fixed oils do : they do not 
form soap with alkalies. 

VEGETABLE ACIDS. 

Acids are numerous in the vegetable kingdom, and possess 
much interest and importance ; but the limits of this book will 
not admit of a detailed account of them : they constitute but a 
small part of the plants from which they are derived. The 
most important are the acetic, oxalic, tartaric, citric and malic 
acids. The general properties of acids have already been 
described. 

VEGETABLE ALKALIES. 

Alkalies exist in all plants, and always in the form of salts, 
or in combination with an acid. Potash, lime and soda, 
although found in plants in greater abundance than the 
others, are not vegetable alkalies: the true vegetable alkalies 
are morphia, quinia, strychnia, &c. 

Metallic oxides and earths found in plants have already 
been named, and their properties will be described in another 
chapter. The few organic proximate elements of plants which 
have been briefly described, are but a comparatively small 
part of the whole number : only such as possess most interest, 
and are most common and necessary to be understood, have 
been selected. 

diastase. 
Diastase is a white, tasteless powder, formed during the 
process of malting barley, and also during the germination of 
plants. The properties of diastase are not well understood, — 
it is supposed to be the first product of the putrefactive fer- 
mentation of vegetable gluten and albumen. 



CHEMISTRY. 65 

EXTRACTIVE MATTER. 

JExtradive matter, (apotheme,) exists in vegetables, and may- 
be obtained by steeping them in liot water, and then evapo- 
rating the water, when a brown powder will remain, which is 
but slightly soluble in water or alcohol, but soluble in alkalies. 
Its nature Ls not well understood ; Dr. Kane, however, supposes 
it may be identical with idmic or humic acid. It is not nutri- 
tious. 

TANNIN". 

Tannin exists in the bark of most trees, but most abun- 
dantly in the bark of the oak, horse chesnut and hemlock. It 
is an astringent brownish powder, soluble in alcohol and water. 
It has arf astrino-ent taste and is destitute of odor : it combines 
mth animal gelatine and forms an insoluble precipitate ; hence 
by soaking the skins of animals in a solution containing tannin, 
it is converted into leather, which is no longer subject to 
putrefaction. It is composed of carbon, hydrogen and oxygen : 
it is not nutritious: it precipitates most metalHc solutions, and 
is hence used in practical chemistry as a re-agent. 

COLORING MATTER. 

The matter which constitutes the basis of vegetable colors 
is found in most plants. " The organic coloring principles, 
[says Dr. Fownes,] with the exception of one red dye, cochi- 
neal, are all of veo-e table origin." The art of colorino- is based 
upon the affinity Avhich exists between the coloring matter and 
the fibres of the different fabrics to be colored. This is 
stronger in woolen than in cotton and hnen ; hence in dyeing 
the two latter a. third substance, called a mordant, is used, 
which strengthens their affinity: for this purpose, salts of 
alumina, iron and tin are used. 

The coloring principle of vegetable blues is indigo: that of 
madder red is alizarine: of madder yellow, xanthine: the 
green color of plants depends upon a substance called chloro- 



C6 SCIENTIFIC AGRICULTURE. 

jplmjlle. The coloring principle of logwood is hccmatoxyline : 
carmine is a beautiful pink color derived from the cochineal 
insect: several substances produce yellow and brown. 

Nearly all vegetable colors are destroyed by the action of 
solar light, — and all of them, without exception, by the action 
of chlorine gas: acids and alkalies destroy or change them. 
No coloring principle has yet been found in plants, capable of 
being transferred to other bodies so as to produce a green: 
greens are therefore produced by the action of blues upon a 
base of yellow. Substantive colors are those which combine 
directly with the fibres of cloth without the intervention of a 
mordant: adjective colors require the assistance of a mordant 
to make them permanent. 

INORGANIC ELEMENTS OF PLANTS. 

Besides the organic elements which enter into the compo- 
sition of plants, and which, as before stated, are themselves in 
most cases composed of the four principal elements, carbon, 
oxygen, hydrogen and nitrogen, — there are several inorganic 
substances, which are constantly present in all plants, and in 
about the same relative proportions in the same ^lant in all 
cases. These are in combination with the gases and with one 
another. Chlorine, iodine, sidphur, phosphorus, potassiuin( 
sodium, calcium, magnesium, aluminum, silicon, iron, and 
manganese. 

CHLORINE. 

Chlorine is a yellowish green gas, having a pungent, suffo- 
cating odor ; it is soluble in water, extinguishes a lighted taper, 
has a specific gravity of 2.47, and when submitted to the 
pressure of four atmospheres, is condensed into a limpid 
yellow liquid. This gas is a supporter of combustion, but not 
of animal fife : a piece of phosphorus, gold leaf, potassium or 
sodium, introduced into it, inflame and burn spontaneously. 
Chlorine has but fittle affinity for oxygen, its chemical pre- 



CHEMISTRY. 67 



• 



ferences being principally hydrogen and tlie metals : it is not 
found in an uncombined state in nature. The most charac- 
teristic property of this gas is its bleaching power ; it decom- 
poses readily the most permanent -organic coloring principles; 
the presence of water is necessary to develop, the bleaching 
properties of chlorine. This gas is a highly disinfecting agent. 
Common salt is a compound of chlorine and sodium. 

IODINE. 

Iodine is a solid substance, in shining lead-colored scales. 
It is volatiHzed or converted into vapor by a moderate heat, — • 
the vapor has a beautiful ^iolet color, and an odor resembhng 
chlorine. It is soluble in water, and more perfectly so in 
alcohol. • It is obtained from the ashes of marine plants, but 
has not as yet been detected in any of the plants cultivated 
for food. Both plants and animals confined in the vapor of 
iodine soon perish. 

SULPHUR. 

Sulphur exists in considerable abundance in nature; the 
most common source of the sulphur of commerce is volcanic 
action : it is subhmed and thrown out in large quantities from 
the earth,-s-it exists also in natural waters. It is a yellowish 
green powder, having little taste or smell, — it is but slightly 
soluble in water. When heated it exhales white fumes of an 
intensely suffocating odor, — these fumes are called sulphurous 
acid. This gas is destructive to both animal and vegetable 
life : it possesses bleaching properties. There are several 
compounds of sulphur which are essential to the growth of 
vegetation. Sulphur is furnished by the soil to the roots of 
slants, from the sulphates of lime, potash, soda, magnesia, and 
immonia; but principally by the salt ammonia. 

PHOSPHORUS. 

Phosphorus is a solid substance, having the consistence of 
wax, and of a pale yellow color: when exposed to the air, it 



68 



SCIENTIFIC AGRICULTURE. 



takes fire spontaneously and burns with a pale blue flame, 
scarcely visible except in the dark. When heated, however, 
it takes fire and burns with a brilliant flame and intense light, 
with the evolution of dense white fumes. 

It is not foui^ in nature in an uncombined state, " and is 
not known [says Johnston ] to be susceptible of any useful 
application in practical agriculture." Phosphoric acid results 
from the combination of the fumes of burning phosphorus 
with the oxygen of the atmosphere. It has the characteristic 
properties of acids, and unites with hme, soda, and potash, to 
form phos2)hates. This acid is not found in nature in a free 
state, — but the compounds of phosphorus are extensively dif- 
fused throughout nature, and are essential to the growth of 
all cultivated plants. 

CATALOGUE OF THE COMPOUNDS DERIVED FROM THE INORGANIC 

ELEMENTS OF PLANTS. 



Sulphurous acid, 

Sulphuric " 

Phosphoric " 

Potash, 

Soda, 

Lime, 

Magnesia, 

Chloride of Potassium, 

" Sodium, 

" Calcium, 

" Magnesium, 

First Chloride of Iron, 

Second " " " 

Carbonate of Soda, 

Bi-carbonate " 

Nitrate 

Sulphate « 

Phosphate " 



Alumina, 
Silica, 

Protoxide of Iron, 
Peroxide " 

Protoxide of Magnesia, 
Sesquioxide " 

Peroxide " 

Sulphuret of Potassium, 
" Sodium, 

" Calcium, 

" Iron, 

Bi-sulphuret " 
Carbonate of Potash, 
Bi-carbonate " 
Sulphate " 

Nitrate " 

Binoxalate " 

Bitartrate " 



CHEMISTRY. 



69 



Bi-pliospliate of Sodca, 
Carbonate of Lime, 
Sulphate " 

Nitrate « 

Phosphate " 

Bi-phosphate " 

Silicate of Potash, 

Bi-silicate " 

Silicate of Soda, 

Bi-silicate " 

Silicate of Lime, 
" Mao'nesia, 

Carbonate of Magnesia, 

Sulphate 
These are not all the compounds found in plants ; but they 
are those which exist in most plants, and Avhich are more or 
less essential, in some quantity, to the healthy growth and 
maturity of the various parts of the vegetable organization. 



Phosphate of Potash. 
Bi-phosphate " 
Carbonate of Magnesia, 
Bi-carbonate " 

Sulphate • " 

jSltrate " 

Phosphate " 

Sulphate of Alumina, 

Phosphate " 

Silicate " 

Carbonate of Iron, 

Sulphate " 



CHAPTER V 



FERMENTATION. 



Fermentation is a peculiar decomposition or transformation of the ele- 
ments of a complex organic substance, by the agency of some 
external disturbing force different from ordinary chemical attraction, 
as heat, air, or contact with some other body similarly affected. 

Liebig. 



The compounds which are capable of fermentation, or any 
similar change, are those in which a weak affmity or equilib- 
rium exists, and is consequently easily disturbed and overcome, 
by several different agencies, such as heat, acids, oxygen, 
chlorine, &c. If we add to a solution of sugar and water a 
small quantity of any organic substance which is itself in the 
act of slow decomposition, the sugar becomes afifected in the 
same way, and is changed to carbonic acid and alcohol. 

This is called vinous fermentation: another form of \inous 
fermentation is that which takes place in the transformation of 
must into wine: when the expressed juice of the grape is 
exposed to a temperature of about 70° F., its own temperature 
is raised, carbonic acid is given off, a scum rises to the surface, 
and a sediment subsides to the bottom, and the must is changed 
to wine. This is the simplest case of fermentation : yeast is 
peculiarly effective in producing this kind of fermentation. Yeast I 
is the product of the vegetable gluten or albumen in fermen- ' 



CHEMISTRY. 7l 

tation. The fermenting power of yeast is destroj^ed by boiling, 
by alcohol, by many salts and acids, and generally by all those 
agencies wliich render albumen and gluten insoluble. 

Besides yeast, there are several vegetable substances, as 
gluten, albumen, caseine and fibrine, which, when in a state of 
decomjDOsition, act as ferments on a solution of sugar. The 
same effect is produced, also, by animal gluten, albumen, flesh 
and blood, after putrefaction has commenced. When wine 
and cider are exposed to the air at a certain temperature, a 
second fermentation, called the acetous, takes place, and they 
are changed to vinegar : during this change oxygen is absorbed 
from the air, and carbonic acid is evolved : '* but the apparent 
cause of the formation of vinegar is the abstraction of hydrogen 
from the^lcohol, so as to leave the remaining elements in such 
proportions as to constitute acetic acid. The presence of nitro- 
gen seems to be necessary to the composition of all ferments. 
The precise nature of the changes wliich take place during 
fermentation is not yet precisely understood or explained. 

" We can offer no other explanation of these facts of fermen- 
tation than this, that when a body in a state of progressive 
change, the particles of whirh are in a state of motion, is 
placed in contact with another body, the particles of which 
are in a state of unstable equiUbrium, the amount of motion 
mechanically commmiicated to the particles of the lattei- from 
those of the former is sufficient to overturn the existing equi- 
librium, and by the formation of a new compound, establish a 
new equilibrium more stable under the given circumstances." 

[Turner. 

METAMORPHOSIS OF ORGANIC ELEMENTS. 

There are certain organic compounds which, from the com- 
plexity of their constitution and consequent weakness of affinity, 
are peculiarly disposed to decomposition and change of elemen- 
tary form. Among these are starch, gum, sugar and lignine, 
the first three of which are composed of the same elements in 
the same proportions. 



72 SCIENTIFIC AGRICULTURE. 

These are disposed to change of elementary form whenever 
the balance of opposing forces is destroyed : that is, whenever 
by the agency of some external disturbing force, as heat, air or 
water, the affinity wliich holds these elements together is over- 
come, the elements are separated entirely, or one element is 
replaced by another : and thus lignine is changed into starch, 
starch into sugar, &c. 

This intimate relation of composition among these substances 
renders it plain that they may all occur together in the same 
plant, and that when one occasionally disappears from the 
plant, it may be replaced entirely or in part hj another ; and 
this is really the case. Lignine or woody fibre may be changed 
to starch by boiling sawdust in water so as to separate all 
soluble matters, then drying it in an oven and fermenting with 
yeast. In this way the author has made bread of beech wood, 
which was but little inferior to that made from unbolted wheat 
flour. 

Woody fibre may be transformed to starch, also, by the 
action of sulphuric acid or caustic potash. 

Starch, when gradually heated to a temperature not ex- 
ceeding 300° F., acquires a brownish tint,. and is changed to 
gum. Starch may be changed to gum by dissolving it in hot 
water, and allowing it to remain in a cold place for a few 
months ; or it may be changed more rapidly by boihng it in 
water for a length of time. By the action of sulphuric acid, 
also, starch may be changed to gum, and this gum again into 
grape sugar. 

Gum arahic may be changed to sugar by the agency of 
chalk and sulphuric acid. — [Bcrzehus. 

Cane sugar which is crystalized, if heated to a temperature 
of 360° F., gives off two atoms of water and is changed to 
caramel: this is an uncrystalizable sugar, containing one pro- 
portion of oxygen and one of hydrogen less than cane sugar. 
Cane sugar may be changed to grape sugar by digesting it in 



CHEMISTRY. 73 

dilute sulphuric acid at a gentle heat. The formula for these 
two varieties of sugar is as follows: 

Cane Sugar, Dry Qrape Sugar. 
Carbon, 12, Carbon, 12, 

Hydrogen, 10, Hydrogen, 12, 

Oxygen, 10. Oxygen, 12. 

From the fact that we can produce these metamorphoses at 
pleasure, it is easy to conceive that they may take place even 
more readily and perfectly in the vegetable organization, than 
by the comparatively clumsy operations of the chemical labor- 
atoiy. This is one of an infinite number of the beautiful 
processes of nature which modern chemistry has discovered. 

4 



PART II. 



GEOLOGY. 



CHAPTER I. 

Geology investigates the nature, composition, origin, struc- 
ture, and arrangement of the materials of ^vhich the earth 
is composed. Geology may be divided into three parts, \iz : 
1. Chemical Geology, which investigates the .chemical nature 
and composition of the ^'arious materials of which the earth 
is made up. 2. Mechanical Geology, which treats of the 
arrangement, structure and relative position of these various 
materials. 3. Historical Geology, which treats of their relative 
ages and origin, and the changes which they are undergoing.* 

Every part of the earth, including air, and water, except 
undecomposed animal or vegetable matters, is regarded as 
mineral. 

The term rock, in geological language, includes besides the 
sohd parts of the globe, the loose materials, such as sand, 

' * This division is proposed by the author, and is, like all the otliers 
which have been proposed, imperfect, and, in some respects, objec- 
tionable. It has the advantage of being plain and convenient: such a 
division, however, whether perfect or imperfect, is not indispeusible 
to the successful study of Geology. 



GEOLOGY. 75 

gravel, clay, soils, <fec., which constitute a part of its crust. 
"Taken ar ^i^ ^e, the earth is about five times heaver than 
water, anc. . . id a half times heaver than common rocks.'* 
The density ut the earth increases from the surface towards 
the centre. The surface of the earth beneath the ocean, as 
well as the dry land, is elevated into hills, with plains and 
valHes intervening. The mean depth of the ocean is estimated 
at between two and three miles ; from the phenomena of tides, 
the Atlantic, in its middle part, is supposed to be over nine 
miles deep. 

DEFINITION OF TERMS. 

Rocks are divided into two great classes, viz : stratified and 
unstratified. 

Stratification consists of the division of a rock into regular 
parallel planes or leaves, varying in thickness from that of thin 
paper, to several yards. Strata are often tortuous and variable 
in thickness in different parts of the same lamina or layer; 
" nevertheless, the fundamental idea of stratification, is that of 
parallelism in tlie layers." " The term stratum is sometimes 
employed to designate the whole mass of a rock, while its 
parallel subdivisions are called beds, or layers." So, iilso, of 
sand, clay, gravel, &c. 

The term bed is used to designate a layer or mass of rock 
more or less irregular, lenticular or wedge shaped, lying 
between the I^ljqys of another rock, — such as beds of coal, 
gypsum or iron. 

Fig. 1. 




- Without lamina. 
With waved lamina. 

- Finely laminated. 
Coarsely laminated. 

- Obhquely laminated. 
Parallel lamina. 



76 



SCIENTIFIC AGRICULTURE. 





"A seam is a thin layer of rock that separates the beds or 
strata of another rock, as a seam of coal, hmestone, &c." 

A joint is a separation of rocks, both stratified and unstrati- 
fied, into masses of some determinate shape : joints are more 
or less parallel, and usually cross the beds obliquely. 

Cleavage planes are divisions in rocks, wliich do not coincide 
with those of stratification, lamination or joints. They are 
supposed to result from a crystafine arrangement of the par- 
ticles of the rock. 

Cleavage Planes. 
A A 

N \ A V / \ 

A A 

[Fig. 2 exhibits the planes of stratification, B, B, — the joints, A, 
A, A, A, and the slatj^ cleavage, d, d.] 

Horizontal strata are those that have Httle or no inclina- 
tion, — but Me parallel 
with the horizon : this 
position, however, is 
rare, almost all strata 
beino' more or less inclined. 

The Dip of strata signifies the angle which they form 
with the horizon. 

Outcrop. — When Fig. 4. Dip and Outcrop, 

strata are uncovered ^ i*..^!**^ l>^ 

above the surface, 
or protrude from the 
side of a liill so as to be visible, they are said to crop out. 

An Escarpment is formed when strata terminate abruptly, 
s'^ ns to form a precipice. • 



Fig. 3. Horizontal Strata. 






GEOLOGY. 77 

A Fault in a rock is the dislocation of strata, so that their 
continuity is destroyed, and a series of strata on one or both 
sides of the fracture are forced from their original position, 
and raised one above another, or moved laterally. Faults are 
generally filled with clay, sand and fragments of other rocks. 

A Gorge is a wide and open fissure or fault: when still 
wider, with sloping sides and rounded at the bottom, it is 
called a valley. 

Tie. 5. Dvke. 

A DyJce is a mass or wall ( t 
rock interp^« ' between tli 
ends of a disioocition, so as 1 »j 
break their continuity: dyk( 
rarely send off branches. 

Veins are portions of rocks smaller than dykes, proceeding 
from some large mass, and ramifying through a rock of a 
difi*erent kind. Metallic veins were originally melted metals, 
which were injected into the fissures and cre\'ices of rocks by 
some subterranean force. 

Fossil. — This term includes those petrified remains of plants 
and animals which are found in alluvium, or imbedded in solid 
rock, and constituting part of its structure. 

Formations. — The term formation is used to designate a 
group of rocks having some character in common, — either in 
relation to age, origin or composition. Every formation con- 
sists of several varieties of rock, all agreeing in certain qualities, 
and occupying such relative situations as to indicate that they 
were formed during the same period and under similar circum- 
stances. Thus we speak of graywacke formation, gneiss for- 
mation, coal formation, <fec. 

CLASSIFICATION OF ROCKS. 

Many different classifications of rocks have been proposed, 
none of which is entirely unexceptionable : the present state of 
Geological science will admit of our adopting any one of them, 



78 SCIENTIFIC AGRICULTURE. 

without the risk of incurring much inaccuracy. It is not 
desio-ned in tliis treatise to Q;ive a full classification of all the 
rocks, with a detailed description of their characters, but only 
the outlines of classification, and a brief description of such as 
are deemed most important to our present pui-pose. 

Notwithstanding the apparent discrepancies among the 
systems of classification, "in all the essential principles, geolo- 
gists are nearly agreed : they all admit one class to be stratified 
and another unstratified : — one portion of the stratified rocks 
to be fossiliferous and another portion not fossiliferous : and 
they generally agree also as to the extent of the different 
distinct formations. Now these three principles are all that 
are essential for classification ; and some of the best geologists 
hmit themselves to these." — [Hitchcock. 

One very common and natural classification of rocks is, into 
two great families, viz: stratified and unstratified. We shall 
give the outUnes of two others, viz : the improved Wernerian, 
and that of Mr. Lyell. 

IMPROVED WERNERIAN CLASSIFICATION. 

. ( Alluvium, 

Alluvial. - 7^ •,-. 
{ Drijt. 

Tertiary. \ Tertiary strata. 

Chalk, 

Green sand. 
We aide n. 
Oolitic system. 
Secondary. ^ Lias, 

New red sandstone. 
Coal formation, 
Carbon iferous limesto ne, 
Old red sandstone. 

m ^ j Silurian system, 

Graywacke system. 



Primary. 



GEOLOGY. 79 

Clay slate, 
Quartz rock, 
Hornblende slate, 
Talcose slate. 
Primary limestone. 
Serpentine, 
Mica slate, 
^ Gneiss. 

Alluvium. — If we commence at the surface of a soil which 
has been formed by the successive deposits of annual floods, or 
the freshets of rivers, and descend to the lowest class of rocks, 
viz, — the primary, — we shall pass through the different classes 
of rocks in the following order. The first few feet, usually 
less than one hundred, is composed of vegetable and earthy 
matters, loam, sand and fine gravel, deposited in hor:z:ntal 
beds. 

Drift. — The second formation is made up of coarse and fine 
sand, gravel, and sometimes ^ay, containing rounded masses 
of rock, called boulders. This mixture is often horizontally 
stratified. 

Tertiary. — The third series is composed of clay, sand, gravel 
and marl, with occasional beds of quartzose and calcareous 
rock, which have been deposited from water in a quie. &tate. 
This series also contains many organic remains : the strata are 
usually horizontal, but sometimes they have a small dip. 

Secondary. — The next series below the tertiary is composed 
mostly of solid rocks: these rocks are made up mainly of sand, 
clay and pebbles cemented together: these are interstratified 
by organic remains and several varieties of hmestone, — they 
usually dip at various angles. The older fossihferous rocks 
included in this series are sometimes called transition rocks. 

Primary — Transition. — This class includes both stratified 
and unstratified crystaline rocks, which are destitute of organic 
remains. The unstratified rocks lie below the stratified ones 
wherever they have been found : hence it is inferred that the 
interior of the globe consists of unstratified crystaline rock^ 



GEOLOGY. 81 

lyell's classification. 
Mr. Lyell comprehends all the various rocks which compose 
the crust of the earth in four great classes, depending for their 
distinctive characters on their orioin and age. These are 
named as follows. 

f Aqueous, 
j Volcanic, 
I Plutonic, 
1^ Metamokphic. 

Aqueous Rocks. — This class, called also, the sedimentary 
rocks, covers a larger portion of the earth's surface than any 
of the other three classes. They are stratified, and supposed 
to have been deposited by water, both running and quiescent: 
they contain fossils, shells and coals. 

Volcanic Rocks. — This class of rocks has been produced, 
both in ancient and modern times, by the action of volcanic 
fires or subterranean heat "They are for the most part 
unstratified, and devoid of fossils:" they are more partially 
distributed than aqueous formations, at least in respect to 
horizontal extension. 

Plutonic Rocks. — This class of rocks has been formed " at 
great depths in the earth, and they have cooled and crystalized 
slowly, under enormous pressure, where the contained gases 
could not expand. They are more crystahne than the others, 
have no ca\ities, and contain no organic remains. They lie 
below, and are older than all others. 

Metamorphic Rocks.* — These rocks, according to Mr. Lyell, 
"were originally deposited from water in regular strata, and 
afterwards metamorphosed or changed by subterranean heat, 
so as to assume a new and difierent texture. They contain no 
pebbles, pieces of imbedded rock, nor organic remains, and are 
often crystaline, as gTanite. They vary in color and compo- 

* This class is considered as merely a h}7)othetical division by many 
of the best Geologists. ^* 



82 SCIENTIFIC AGRICULTURE. 



I 



sition. The degree of heat which produced the change in 
those rocks was less intense than that which produced the] 
plutonic class, and was doubtless assisted by gaseous agency. 
. We have thus given a brief outline of two systems of classi- 
fication, without, however, giving the reasons in favor of any 
theory or classification. Our hmits will not admit of a sub- 
di\dsion of the classes into orders, genera and species, — ^much 
other useful matter must also be excluded. A few of the 
most important rocks and the metalloids have been described, 
being thought indispens ible to a proper understanding of the 
principles of geology and the constitution of soils. 



CHAPTER 11. 



GRANITE. 



Granite is a compound of three minerals, viz: quartz, 
feldspar and mica: the different ingredients are sometimes in 
coarse crystaline fragments, and in other cases so fine as to 
be scarcely distinguishable by the naked eye. Granite is 
most usually of a whitish or flesh color, — it has, however, other 
tints. Feldspar predominates in the composition of granite, 
while the mica is in the smallest quantity. "These three 
minerals are united in what is termed confused crystalization: 
that is, there is no regular arrangement of the crystals in 
granite as in gneiss." The coarse grained granites contain 
the most interesting specimens of simple minerals, while the 
finer kinds are best for architectural purposes. 

Granite often preserves a uniform character throuo-h a erreat 
extent of country, forming roimded hills: it is sometimes, 
though not generally, subdiAaded by fissures into masses of a 
cuboidal and columnar form. Y\^here it is naked at the 
surface, and exposed to atmospheric changes and action, it is 
in a crumbling state, and covered with a scanty vegetation. It 
is remarked by Lyell, that all granitic rocks are frequently 
observed to contain metals, at or near their junction with 
stratified rocks. 

Granite is supposed to be the oldest, most abundant and 
important of all the unstratified rocks. There are several 



84 SCIENTIFIC AGRICULTURE. 

varieties of granite, viz: graphic granite^ syenitic granite^ 
talcose granite^ porphyritic granite, curite and pegmatite: 
these varieties have various proportions of each* element, and 
also various colors and crystaline arrangement. 

SYENITE. 

Syenite is composed of quartz, feldspar and hornblende : it 
is sometimes called syenitic granite, — it has received this name 
from the ancient quarries at Syene in Egypt. It has the 
appearance of granite, but its composition is different, horn- 
blende being substituted for the mica in granite. Syenite, 
according to Lyell, frequently loses its quartz and passes insen- 
sibly into syenitic greenstone. 

PORPHYRY. 

Rocks of a homogeneous, compact structure, containing some 
other crystaline mineral, of the same age with the base, are 
called porphyry. The base, or principal mass of the rock, may 
be greenstone, claystone, basalt, or other rock containing crys- 
tals of feldspar, augite, olivine, &c. 

" True classical porphyry, [says Dr. Hitchcock,] such as was 
most commonly employed by the ancients, has a base of com- 
pact feldspar, with embedded crystals of feldspar." The term 
porphyry is indefinite, and does not belong to any particular 
rock. The term is of Greek origin, and signifies purple, — but 
this rock is of a variety of colors, and is the hardest and most 
durable of all rocks. 

GREENSTONE. ■ 

This is a granular rock composed of feldspar and hornblende ; 
the feldspar is imperfectly crystalized: greenstone sometimes 
contains augite and iron also. The hornblende predominates 
in quantity over the other ingredients. 

TRACHYTE. 

Trachyte is a porphyritic rock of a grayish or whitish color, 



GEOLOGY. 85 

composed princiiDally of glassy feldspar, containing also crystals 
of feldspar, mica, hornblende, and sometimes iron. It is rough 
and harsh to the touch, — hence its name from the Greek word 
traclms, (rough:) it occurs in vast quantities in Europe and 
South America, in volcanic regions, but is not found in the 
United States. 

BASALT. 

"Basalt consists of an intimate mixture of augite, feldspar 
and iron, to wliich a mineral of an olive green color called 
olivine, is often superadded in distinct grains or nodular 
masses." The iron is usually magnetic, and is sometimes 
accompanied by the metal titanium, hence the name " titani- 
ferous iron." Augite is the predominant element in this rock: 
basalt passes insensibly into most other varieties of trap rock. 
True basalt does not occur in the United States. 

AMYGDALOID. 

Any rock containing almond shaped pieces of some other 
mineral, as quartz, chalcedony, agate, calcareous spar, or zeo- 
lite, may be denominated amygdaloid : the base may be wacke, 
basalt, greenstone, or any other trap rock. Some amygdaloid 
rocks have the almond shaped cells or cavities, which are 
empt}^ and glazed on their sides by a glassy coating, showing 



their io-neous orioin. 



SERPENTIXE. 



Tliis is a greenish colored rock, containing, according to Dr. 
Hitchcock, 40 per cent, of magnesia, — it is a hydrated silicate 
of magnesia. Serpentine sometimes contains diallage, steatite, 
talc, and some iron. It is classed by most authors among 
unstratified rocks. Comparatively it is not a rock of great 
extent: it is often associated v>'ith talcose slate. 

LAVA. 

Under the term lava, are embraced all the varieties of 



86 SCIENTIFIC AGRICULTURE. 

melted matter thrown out by volcanoes: these are composed 
almost entirely of feldspar and augite. Some lavas are por- 
phyritic, and contain imperfect crystals, " derived from some 
older rocks, in which the crystals pre-existed, but were not 
melted, as being more infusible in their nature." 

When lava is cooled in the open air, it is light, porous and 
spongy, and floats on water, as is the case w^ith pumice stone ; 
but when cooled under great pressure, at considerable depths 
below the surface, solid rock is the result. 

There are several varieties of lava, varying in composition, 
and also of different colors, as gray, whitish, greenish and dark: 
fragments of granite and other rocks, — several metals and 
gases, water, sulphur, mud, glass, and* various salts and acids, 
are ejected from the craters of active volcanoes. 

GNEISS. 

Gneiss is composed of quartz, feldspar, and mica, and some 
specimens contain hornblende. This rock is essentially the 
same as granite, except it is stratified. The laminated struc- 
ture becomes obscure where the gneiss passes into granite; 
its stratification is remarkably regular in some specimens, and 
in others tortuous and irregular. This rock is said to be very 
extensive in the United States, particularly in New England. 

QUARTZ. 

This rock is composed either of an aggregate of fine grains 
or crystals compacted together, or of a solid homogenous 
mass of quartz, sometimes containing feldspar, mica, horn- 
blende, talc or clay slate. " In these compound varieties, [says 
Hitchcock,] the stratification is remarkably regular; but in 
pure granular quartz, it is often difficult to discover the planes 
of sti-atificatlon." 

It is alternated or interstratified with all the primary rocks, 
in which case its structure is regular. Some quartz is capable 
of sustaining a powerful heat without cracking or other 
change, — hence it makes an excellent fire stone. 



GEOLOGY. - 87 

HORNBLENDE SLATE. 

Hornblende predominates in this rock, over the various 
quantities of quartz, feldspar and mica which it sometimes 
contains. When it contains much feldspar, it is not slaty, but 
resembles greenstone. It is of a dark color, commonly asso- 
ciated with, and passes insensibly into clay slate, mica Slate 
and gneiss. 

CLAY SLATE. 

Tliis rock is composed mostly of fine clay, and is usually 
more or less dark and shining from the mixture of chlorite and 
black lead which it contains. " It may, [says Lyell,] consist of 
the ingredients of gneiss, or of an extremely fine mixture of 
mica and quartz, or talc and quartz." It passes insensibly 
into mica slate, talcose slate, or hornblende slate : on the other 
hand it passes into unconsohdated clay. 

Clay slate is the kind used for roofing: it varies in color 
according to its composition, from greenish or bluish gTay to 
lead color. This rock, as weU as the following is used for 
whetstones: the best hones are compact feldspar, and are 
erroneously supposed to be petrified wood. 

MICA SLATE. 

. This rock is a compoimd of quartz and mica, the mica being 
in the greatest quantity. This is one of the most common 
and abundant of the stratified rocks. It sometimes contains 
beautiful twelve-sided crystals of garnet in considerable abun- 
dance: beds of pure quartz also occur in this rock. 

SANDSTONE. 

Sandstone is a siliceous rock made up of an aggregate of 
rounded o-rains of silex, sometimes coherino' together without 
any visible cement ; but more commonly bound together by a 
•yaiaU quantity of calcareous matter, iron or clay. There are 



88 SCIENTIFIC AGRICULTURE. 

various gradations of this rock, from, the loosest sand to the 
hardest silex. When the grains of silex are coarse, the rock 
is called grit: if the grains are rounded pebbles, it is called 
conglomerate: another kind of conglomerate, also, is composed 
of sand and fragments from many different kinds of rock. 
Micaceous sandstone contains silvery scales of mica, which are 
so arranged as to give it a laminated texture. Sandstone is 
colored variously by iron and other minerals. 

PRIMARY LIMESTONE. 

This rock is sometimes in thick beds of wliite, bluish, 
greenish or gray granular marble, such as is used in sculpture : 
it sometimes contains mica, quartz, hornblende, feldspar and 
talc. It is both stratified and unstratified : sometimes beins in 
thick beds without any marks of mechanical arrangement, and 
at others it is in laminated leaves or scales hke slate, of various 
thickness. 

TALCOSE SLATE. 

Talc is the principal ingredient in this variety of slate, — ^it 
is sometimes in a pure state and sometimes mixed with quartz, 
feldspar, mica, hornblende or Hmestone : it is a softish stone, 
valuable for building purposes. There are several varieties. 

Feldspar is of two kinds, viz : potash feldspar, in which pot- 
ash is the alkali; this is the common kind: soda feldspar, 
(albiti,) in which soda is the alkali. Other varieties are men- 
tioned, but their composition is not peculiar. 



Composition of Feldspar. 

Silica, 65.21 

Alumina, 18.13 

Potash, 16.66 

100.00 



«i 



OBOLOGY. 85 

Composition of Basaltic Hornhlende. 

Silica, ' 42.24 

Alumina, ^ 13.92 

lime, 12.24 

Magnesia, 13.74 

Protoxide of Iron, - - - - 14.59 
Oxide of Manganese, - - - - 0.33 





97.06 


Composition of Mica. 


i 
1, 


Silica, 


46.10 ^ 


Alumina, ------ 


31.60 


Protoxide of Iron, - - - - 


8.65 


Potash, ------ 


■ 8.39 


Oxide of Magnesia, . _ . 


1.40 


Fluoric Acid, 


1.12 


water, 

• 


1.00 



98.26 

CHALK. 

Chalk is similar in composition to carbonate of lime, viz: 
carbonic acid, 44, — hme, 56, — 100. It is a pulverizable rock, 
of several varieties, -which have resulted from the impurities 
"which were deposited with it. The chalk beds contain great 
quantities of flint, which is dispersed through them in small 
masses. Chalk also contains organic remains : it is a durable 
building stone, and is used for docks, &c. ; some ancient 
buildino's are of chalk : no chalk has been found in America. 

ROCK SALT. 

This cannot be considered a rock, but yet it occurs in vast 
beds, and in connection with rocks, at gTeat depths in the 
earth. In its pure form it is a transparent crystaline salt, 
having the appearance of flint glass : the impure specimens are 
reddish or bluish, and mixed with sulphate of soda and muriate 



90 SCIENTIFIC AGRICULTURE. 

of magnesia. Its origin is not exactly known ; it is supposed, 
liowcver, to have resulted from the evaporation of sea water. 
It is found in Spain, Poland, Hungary, Germany, and in some 
parts of Asia and America. 

COAL. 

Mineral or fossil coal is of several varieties, differing in 
density and weight, and of a dark color, varying from bro^\^l to 
jet black. It is composed of carbon and bitumen, and usually 
contains some other matters. Coal is undoubtedly of vegetable 
origin : as evidence of this, the organic structure of coal can be 
seen in some specimens so distinctly that about three hundred 
species of plants have been discovered in the various kinds. It 
contains also many species of fossil animals. 

Coal beds vary in thickness, from a few feet to three thou- 
sand or more, — and are often several miles in length. The 
manner in which such immense masses of veo*etable matter 
have accumulated during the lapse of ages, may be conceived 
by reference to a single example. 

"According to Bringier, the quantity of timber which 
drifted into the Atchafalaya, an arm of the Mississippi, during 
an overflow in 1812, amounted to 8,000 cubic feet per minute. 
The raft thus collected at the mouth of the Red River, is sixty 
miles long, and in some parts fifteen miles wide." The quan- 
tity which descends the Mississippi in a few years might 
furnish sufficient matter for the largest coal bed known. 

The varieties of coal are, hroioii coal, or lignite, — hituminous 
coa],— anthracite coal, and grajyhite, or black lead : this consists 
of carbon and iron, — and, according to Dr. Hitchcock, " appears 
to be anthracite which has undero-one a still further minerali- 
zation." " Brown coal is produced from wood, by the separa- 
tion of carbonic acid and hj'-drogen." — [Liebig. 

All these varieties of coal occur in seams or beds, interstrati- 



GEOLOGY. 



91 



fied by sandstone and shales : brown coal is found mostly in 
the tertiary, bituminous in the secondary series, and also with 
new red sandstone and clay. 

Anthracite is found in graywacke, mica slate, limestone, 
gneiss, plastic clay, and almost all stratified rocks. 

Fig. 7. Coal Basin. 




[Fig. 7 is a sketch of the great coal basin of South Wales, in Gieat 
Britain, — which contains seventy-three beds of coal, whose united thick- 
ness is ninety-three feet.] — Hitchcock. 

WELLS AND SPRINGS. 

The water which ftills upon the surface of the earth in the 
form of snow and rain, sinks into the alluvium and passes 
through the loose strata, until it comes to a surface of compact 
clay, or a stratum of continuous rock, which prevents its further 
descent ; here it accumulates until it finds some crevice or other 
means of exit, when it takes its course towards the surface at 
some lower point, and in any direction w^hieh may be given it 
by strata or other impediments, until it issues at the surface in 
the form of a spring. Springs which gush out like a fountain, 
or bubble as though they contain gases, have their origin in 
some liill or ledge of rocks above them, where a considerable 
pressure of Avater is forcing the subterranean stream to its exit. 
Springs often exist on the tops of hills ; and they either origi- 
nate in some other hio-her hills, or are caused bv hydrostatic 
force, or an action like that of a syphon. 

In Allegany and Cattaraugus counties, in this state, these 
springs are common ; the soil here is so springy on the hills 



92 SCIENTIFIC AGRICULTURE. 

tliat they are used as meadows, while the arable plow land is 
in the valleys. Wells are only artificial springs, which are ex- 
cavated or bored from the surface until a natural spring, reser- 
voir, or stream is penetrated. Artesian wells are made by 
boring into the earth and inserting pipes until water is found. 
These wells have been carried to the depth of 300 to 1200 
feet in France. Subterranean streams of considerable magni- 
tude have their courses under hills, strata of alluvium, &c. 
They sometimes issue at the side or base of a mountain, of 
sufficient size and force to propel mills and machinery. 



PART III. 



BOTANY. 



CHAPTER I. 

Botany is tliat branch of natural science wWch investigates 
the nature and character of, and inchides all knowledge in 
relation to the vegetable kingdom. It treats of the structure, 
habits, locality, uses, classification and nomenclature of every 
species of plant known on the globe. 

Botany is di\dded, for the sake of convenience and method, 
into Physiological and Systematic: Physiological Botany 
resolves itself into Anatomy, Morphology and Vegetable Phy- 
siology. 

Anatomy treats of the organic structui*e and relations of all 
the various parts of plants. 

Morphology treats of their form, symmetry, and arrange- 
ment. 

Vegetable physiology treats of all the phenomena of the 
vital functions, as absorption, exhalation, digestion, respiration, 
cu'culation, germination, etc. 

Systematic botany is divided into botanical classification, 
special descriptive botany, glossology, and geographical botany. 



94 SCIENTIFIC AGRICULTURE. 

Classification treats of the proper grouping and arrangement 
of plants according to their natural affinities and characters. 

Special descriptive botany consists in applying correctly the 
generic and specific botanical names to parts. 

Glossology consists in the explanation and application of 
names to all the various organs of plants. 

Geographical hotany treats of the climate, country, zone 
and locahty to which the' various species belong. 

Finally, botany comprehends, in its most extensive sense, a 
knowledge of the relations of the vegetable kingdom to other 
departments of natural objects, and the development of the 
limitless resources of this part of the Creator's vast plan for 
the sustenance and happiness of his creatures. 

PRIMARY DIVISIONS OF PLANTS. 

The vegetable kingdom is divided into two great natural 
families, viz : Phenogamia, or that division which includes all 
flowering plants, and Cryptogamia, or that which includes 
all flowerless plants. i 

These two divisions are further distinguished by the dif- | 
ference in their elementary structure. The phenogamous, or 
flowering plants, abound with the woody and vascular tissues ; i 
while the cryptogamous, or flowerless plants, consist almost 
entirely of the cellular tissue. The phenogamia produce seeds _ 
having the cotyledon and emlryo, — while the cryptogamia f 
produce minute organs called spores, having no such distinc- 
tion of organs. The phenogamia are therefore called cotyle- 
donous, and the cryptogamia, acotyledonous. In the former, 
also, we find a system of compound organs, regularly and sue- ' 
cessively developed, in the order of root, stem, leaf, flower and 
seed, — while the latter appear to be "simple expansions of 
cellular tissue, without order, symmetry or proportion." « 

CLASSIFICATION OF PLANTS. 

All natural sciences classify their respective objects under 



BOTANT. 95 

certain fundamental divisions. The first of tliese divisions is 
into CLASSES, — the second divides classes into orders, — the 
third di\ades orders into genera, — the fourth divides genera 
into SPECIES, and these are again divided into varieties. 

The number now known on the whole earth, is between 
80,000 and 100,000 distinct species of plants. The classifica- 
tion of plants, and all other natural objects, is founded on the 
resemblance and diflferences, in some one or more points, of the 
individuals of each class, order, &c. 

A CLASS, in natural history, comprises an assemblage of 
objects or individuals, having one or more common charac- 
teristics. Thus the whale, the hoo; and the cow all belono- to 
the class mammalia^ — because they all have red blood, breathe 
by means of lungs, and nourish their young by means of milk ; 
the whitewood, rose and locust all belong to the division phe- 
nogamia and class angeiosperma, — because they all produce 
flowers and woody stems, and bear fruit in capsular vessels. 

An order is a subdivi^on of a class, and divides objects 
into groups, which are distinguished by more minute and 
peculiar points of resemblance than those on which a class is 
based, but still possessing all the peculiar characteristics of 
that class. The lion, tiger, dog and cat, all belong to the class 
mammaha and order ca7'nivora, because they five, in their 
native state, on flesh: the water-cress, turnip and mustard all 
belong to the order crucifera, because they all produce flowers 
having four petals, arranged in the form of a cross. 

" A GENUS is an assemblage of species with more points of 
agreement than difference, and more closely resembhng each 
other than they resemble any species of other groups." This 
is a subdivision of an order. The dog, wolf, lion and cat, all 
belong to the same order, — but, on account of certain dif- 
ferences, the lion and cat belong to one genus, and the dog 
and wolf to another : the apple, cherry, rose and almond, all 



96 SCIENTIFIC AGRICULTURE. 

belong to the order rosacea, but they belong to clifFerent 
genera, according to some peculiarity in the organs of each. 

A SPECIES "embraces all such indi^iduals as may have 
originated from a common stock: such individuals bear an 
essential resemblance to each other, as well as to their common 
parent, in all their parts." This is a subdivision of a genus. 
The white and red clover both belong to the genus trifolium; 
but they differ in some minor points sufficiently to place them 
in different species. 

A variety is a subdivision of a species, and is the last 
distinction made in any system of classification : varieties in the 
vegetable kingdom occur principally in the cultivated species; 
they depend only upon slight differences, as, for instance, the 
same apple tree, rose bush, or potato vine, may produce fruit, 
tubers and flowers of different colors, but still ahke in all essea- 
tial characteristics. 

We see, through the whole vegetable kingdom, a most 
marked analogy and connection, from the minutest organized 
microscopic plant, to the largest forest tree: there are also 
differences so obvious that there can be no doubt of the pro- 
priety of arranging them into different groups according to 
their peculiar characters. 

ELEMENTARY ORGANS OF PLANTS. 

The most simple and elementary form of a plant is that of 
the embryo, which is produced by, and contained in the seed. 
This consists of two parts, viz : the plimmla and radicle. The 
plumula is the part which is afterwards developed into the 
ascending part of the plant, the stem, branches and leaves. 
The radicle is that which becomes the root, and descends into 
the earth in search of food and moisture. The ascending part 
of the young plant is at first merely a minute growing point, 
enveloped in dehcate rudimental leaves, whie^i constitute a 
hud. 



BOTANY. 



97 



Fig- 1- 




TOOT? 



^^m^^ 




f e ^ d c b 

[Fig. 1. — Forms of tissue ; a, cutting of elder pith, cellular; b, cells 
from the gritty centre of the pear ; c, from the stone of the plum — both 
strengthened "by solid matter ; d, woody fibre ; e, spiral vessel with a 
single fibre partly drawn out ; f, vessel with a quadruple fibre. — Wood.} 

The several elementaiy structures of ■which the various 
parts of plants are made up, are called elementary tissues: 
they are five in number, viz: the cellular, woody, vasiforniy 
vascular, and laticiferous. The chemical elements of wliich 
these tissues ar» composed, are enumerated and described in 
works on chemistry. 

Cellular tissue is composed of a series of minute cells 
attached toQ'ether, and havinf>: a more or less regular form. 
Fig. ], a. 

Woody tissue consists of minute tubes, tapering to a point 
at both ends, and adhering by their sides, the end of one tube 
overlapping that of another so as to form continuous threads. 
Fig. 1, d. 

The vasi/orm tissue consists of tubes, large enough to be 
seen by the naked eye in some plants, — as, for example, in a 
transverse section of the oak. In some plants these tubes are 
jointed, or divided by partitions, and in others they are con- 
tinuous. It is through these that the sap rises, and they are 
the laro-est vessels in the veo-etable oro-anization. Fig. 2, a. 

Vascidar tissue consists of spiral vessels, resembling' some- 



9S 



SCIENTIFIC AGRICULTURE. 



Tvhat the woody fibre; tliey contain air, and tlieir internal 
structure differs in various plants. Fig. 2, b. 

The laticiferous tissue is that through which is circulated 
the latex, or nutritious sap. It consists of minute, irregu- 
lar brandling tubes opening into each other, and situated 
mostly in the bark and under side of the leaves. Fig. 2, c. 

The epidermis, or outside bark, is formed of celluar tissue, 
and envelopes the entire plant, except the stigma of the flower, 
and the spong-ioles of the roots. In plants whose bark is rough 
and i-ao-o-ed, as in the walnut and oak, it is not distino-uishable. 

The delicate membrane which may be stripped from the 
iris, or house leek, is the epidermis; this covering of plants 
is perforated by minute orifices or mouths, which open and 
close by the presence or absence of light. The epidermis 
and leaves have several appendages, as glands, hairs, irrick- 
les, thorns, receptacles, and stings, which it is not necessary 
to describe in this treatise. 

Fig. 2. a 




[Fig. 2. — Forms of tissue, &c.; a, annular ducts; b, spiral and annu- ' 
lar at intervals; c, laticiferous tissues; e, stomata of iris, vertical section; 
d, d, green cells at the orifice; f, f, cells of the parenchyma; e, air cham- - 
ber; g, g, epidermis and stomata of yucca; h. stomata closed; the dots 
represent small luminous bodies in the cells. — Wood.'] 



CHAPTER II. 



ORGANS AND STRUCTURE OF THE FLOWER. 



The essential organs of a flower are tliree, viz: the sta- 
mens, the pistils, and the receptacle. These are all the parts 
necessary to the perfection of the seed,— they therefore con- 
stitute a perfect flower: to these, however, is added in most 
flowers, the perianth, consisting of the calyx and corrolla. 

The STAMENS are slender, thread-like organs within the 
" flower " or periantli, around the pistils ; their most common 
number is five : but this varies from one to a hundred. — 
Their office is said to be the fertihzation of the seed. 

The PISTILS are usually slender, larger than the stamens, 
and occupy the centre of the flower : " they are destined to 
bear the seed." They are sometimes numerous, but in 
man37- cases there is only a single one. 

The RECEPTACLE is placed at the end of the flower stalk, 
and constitute, the basis upon which the organs of fructifi- 
cation are usually placed, in such a manner as to encircle it 



Fig. 3. The CORROLLA is the interior 
I part of the perianth, consisting 
'of one or more circles of colored 
leaves of various hues and deli- 
cate texture, situated upon the 
receptacle : these leaves are called 
petals, (Fig. 4, a, a,) — and they may be 



Fig e. 





100 



SCIENTIFIC AGRICULTURE. 



united at the edges, constituting a bell form flower, (Fig. 3,) 
or they may be separate, constituting a wlieel-form flower 



Fig. e. 



Fig. 4. 




The CALYX is the external part of the 
perianth, consisting of a circle of leaves, 
the same in number as those of the 
corroUa, in some cases distinct, and in 
others united: they are usually green: 
these leaves are called sepals. Fio\ 5, a. 

We see now, that a complete flower is 
made up of four regular sets of organs, 
viz: the stamens^ pistils, receptacle, and 
perianth', these organs are arrano-ed in 
concentric luhorls, or ring-s : some of them may be 
suppressed, some superfluous ones may be developed 



Fig. 5. 



i 




absent^ or 
and some 



f 



BOTANY. 



101 



Fig. 6. 



degenerated into those of a different set, as petals into sta- 
mens, flowers into leafy branches, &c. 

The stamen consists of three distinct parts, viz: the Jlla- 
ment, (Fig. 6, a,) the aniher, (Fig. 6, b,) and the pollen. The 

filament is the thread-like part 
which supports the anther at its 
^summit : the pollen is a fine yel- 
low dust of various forms contain- 
ed within the cells of the anther, 
until discharged through its pores 
into the air. 

The 2^istil consists also of three 
parts, \iz : the ovary, the style, 
and the stigma. 

The ovary is the base of the 
pistil which contains the young 
seeds, and which ultimately be- 
comes the fruit Fig. 6, d. 

The style is a prolonged column arising from the ovary, 
and supporting the stigma at its top. Fig. 6, e. 

The stigma is the upper extremity of the style, usually of 

a globular form: it may be either simple or compound, 

according to the structure of the ovary and style. Fig. 6, £ 

The ovules are minute globular bodies in the cells of the 

ovary, which become the seeds of the matured fruit 

The placenta is a fleshy ridge within the cells of the ovary, 
from which the ovules are developed, and to which they are 
attached. 

There are several other secondary and minute parts, be- 
longing to the flower, which it is not necessary or practicable to 
describe here, as it would only burthen the memory with tecii- 
nical terms which would convey but little useful knowledge. 




102 



SCIENTIFIC AGRICULTURE. 



THE FRUIT. 

The ultimate object of the whole vegetable organization 
appears to be the production of fruit; which is the agent 
through which the reproduction of the species is accomplished. 
After the seed is perfected in annual plants, they soon wither 
and die; the flower always precedes the fruit, and is neces- 
sary to its development and perfection. The fruit consists of 
two parts, viz. : the pericarp and the seed, or the seed-covering 
and the seed ; the pericarp is wanting in some plants, but the 
seed is essential in all. In the coniferous plants, as the pine, 
spruce, (fee, the seed is naked and destitute of the pericarp. 

The PERICARP is the part which envelops Fig. 7 

the seed, whatever be its substance or struc- 
ture. Fig. 7. In the peach and plum, this is 
a fleshy, pulpy substance, — ^iii the oak and 
walnut, a dense hard shell : (fig. 8.) 
thus the structure and composi- 
tion of the pericarp varies in dif- 
ferent plants, from a soft watery 
pulp to a dense shell. The pro- 
cess of the ripening of fruit con- 
sists of certain chemical changes produced 
by the action of light, heat and air, and 
peihaps other agents. Pericarps have 
received specific names, according to their 

Fig 9 form and structure ; that of the pea and bean 
is called a pod, — that of the walnut and but- 
ternut is called a nut, — that of the apple and 
pear, a pome, — that of the currant, and whor- 
*tlebeny, a berry, &c. Fig. 9. 

This figure represents the pericarp, or seed 
capsule of the Oenothera. 



risr. 8. 






BOTANY.* " 



103 



THE SEED. 



The seed contains the rudiments of a new plant, and is 
tlie final product of all the complicated and beautiful pro^ 
cesses of vegetation. The essential parts of the seed are, 
the integuments, the albumen and the embryo. 

The integuments are composed of several distinct layers, 
"which constitute the immediate coverings of the other parts. 
The albumen hes next to the integuments, constituting the 
principal bulk of some seeds ; it is a whitish substance, com- 
posed mainly of starch, which, by the chemical changes which 
it undergoes during the process of germination, serves to 
nourislrthe embryo plant. 

The embryo comprises all the rudiments of the new plant: 
it consists of three parts, viz : the radicle, the plumule, and the 
cotyledon. 

The radicle is the part which forms the root, — the phnnule 
Ti^. 10- forms the ascending portion of the plant, — 

the cotyledon is the bulky part of seeds, and 
- , forms the first leaves of young plants, which 
in the garden bean, cucumber, &c., are 
thick, fleshy and oval, Avhen they first rise 
above the surface of the ground: these sup- 
7 port the plant and perform the function of 
leaves until the proper leaves are formed. 

[This figure shows an embryo with its plumule 
and radicle developed from the cotyledon: a, radi- 
cle; b, plumule; c, cotyledon.] 




GERMINATION OF SEEDS. 



termination consists of the first chemical changes and vital 
action, which take place when a new plant is about to be 
produced. 

" When the seed is planted in a moist soil, at a moderate 
temperature, the integuments gradually absorb water, soften 



104 



SCIENTIt'IC AGRICULTURE. 



and expand. The water is decomposed, its oxygen combines 
with the carbon of the starch which has been stored up in the 
tissues. Thus, loosing a part of its carbon, the starch is con- 
verted into sugar for the nourishment of the embryo, which now 
begins to dilate and develop its parts. Soon the integuments 
burst, the radicle descends, seeking the damp and dark bosom 
of the earth, and the plumule rises with expanding leaves, to 
the air and light. The conditions requisite for the germination 

of the seed are, heat, moisture, oxygen, air and darkness." 

[Wood. 
Fig. A. a 




[Fig. A. This cut represents a young dicotyledonous plant, with its 
radicle, a, developed; its cotyledons, c, c, appear in the form of large 
succulent leaves; the plumule is just appearing as a minute point 
between the cotyledons.] 



THE ROOT. 



The roof constitutes the basis of the plant: it serves two 
pui-poses in the vegetable economy, — first to fix the plant 



BOTANY. 



105 



mechanically in the soil and retain it in its position, — secondly 
to absorb from the soil those inoro-anic elements which are 
necessary for its food. The general direction of the root is 
downwards ; but the roots of various plants grow^ at all angles 
from the horizontal to the perpendicular: the principal perpen- 
dicular axis is called the tap root. The number and extent of 
the roots must correspond with those of the stalk and leaves 
of the plants, in order to supply their demand of food from the 
soil. 

Roots do not usually extend to great depths, but keep 
within the hmit of that portion of soil w^hicli supphes their 
proper nutriment. Roots are distinguished from stems and 
branches by the absence of stomata, buds and pith, — and by 
the presence of absorbing fibres. 

The stock, or main body of the root, sends off the fibrils, or 
minute, slender branches of the root, — the delicate, tender 
extremities of the fibrils are called spongioles: these are the 
gromng points, and the organs w^hich absorb from the soil the 
earthy part of the food of all plants. If some trees, as the 
■willow or currant, be inverted in the soil, the branches are 
changed to roots, while the roots put forth leaves in the air, 
and the plant grows. 

Roots are of several different forms, which have received 

specific names for the sake 
of convenience. 

Ramose, or hranching 
roots, are those which send 
off many ramifications in 
various directions, like the 
branches of a tree: such 
are the roots of the oak 



Fig. 11. 




and elm. 



Fig. 11. 



106 

Fig. 12. 



SCIENTIFIC AGRICULTURE. 

Fusiform, or sinndle shaped roots, consist of a 
fleshy stock, tapering downwards to its extremity, 
sending off fibrils, which are its true roots: such 
are the raddish, carrot and parsnep. Fio-. 12 

The nupiforin root is a variety of 
the fusiform, in which the neck or 
upper part swells out, so that its 
diameter equals or exceeds its length. 
The turnip and turnip-raddish are 
examples. Fig. 13. 

^'^'it# M Fibrous roots are made up 
of numerous small thread-hke 
roots, attached directly to the, 
stalk, without any neck or main 
root: such are the roots of most, 





o-rasses. 

o 



Fio". 1' 



Fasciculated roots differ from 
the fibrous in having some of their fibres thickened and fleshy^ 
as in the dahlia and peony. 

Tuherous roots consist of fleshy, roundish knobs or tumors,* 
rig- 15. at or near the extremity of the stalk, as laf 

the orchis : " the potato was formerly classed 
among tubers,— but as it uniformly bears 
buds, it is classed among stems." Fig. 15. 

Gramdatcd roots consist of many smalt 
rounded bulbs connected together by fibres 




as in the common wood sorrel. 

Fig. 16. 



Fig. 16. 




BOTANY. 107 

Besides tliese varieties of roots, tliere are several others 
TN'bich are peculiar, and distinguished by not being necessa- 
rily fixed in the soil. 

Aerial roots are those which grow from some part of the 
plant above the surface of the soil in the open air. Some 
creeping plants, as the ground i\y, send forth these roots 
from their joints. The screw-pine also sends off roots which 
are several feet in length before they reach the ground. 
Such roots are often seen in the common maize. 

Floating roots belong to plants which float upon the 
surface of water. The water-starwort is said to float upon 
the surface until flowering, when it sinks and takes root in 
the mud till its seeds ripen. 

The epij^hytes, or plants fixed upon the branches of other 
species, derive their noui-ishment mostly from the air; such 
are some species of moss. 

Parasites are those plants which grow upon other plants; 
and some of whose roots are said to penetrate their tissues 
and subsist upon their juices; while the roots of others are 
aerial, and derive their food from the air; such are the 
mistletoe and dodder. 

Roots are divided again into three varieties, \\z: annual, 
biennial and perennial, according to their duration. 

Annual roots are those which live only one year, and 
must be raised from the seed, sown every spring, — as beans, 
peas and cucumbers. .... 

Biennial roots are those which live two years and do not 
blossom the first season, — but they produce flowers, fruit 
and seeds the second year, and then die : such are the beet, 
cabbage and carrot. 

Perennial roots live several years, — some of them, as 
forest trees, live to a very great age: the grasses, dandelion 
and asparagus are other examples. 



108 SCIENTIFIC AGRICULTURE. 



STRUCTURE AND FUNCTIONS OF THE ROOT. 

The internal structure of the root and stem are similar: 
the fibrils are composed of vascular tissue, inclosed in a cel- 
lular epidermis, Avhich, however, does not extend to the ends 
of the fibrils ; — these ends are naked and spongy, — hence 
they are called spongioles, and have the power of absorbing 
large quantities of water. 

The growth of the root takes place by layers upon its 
surface and the addition of matter at the extremities. The 
fact is considered established, [Johnston,] that the sponoioles 
absorb gaseous as well as aqueous matters, when in contact 
with them. The root absorbs only from its spongioles ; — from 
these it is carried by the vessels of the fibrils to those of the 
main roots, and thence into the stem and to all parts of the 
plant. 1. Both organic and inorganic substances, in a state of 
solution in water, enter the circulation of plants. 2. The roots 
have the power of selecting such substances as are necessary 
for their food, and of rejecting those that are injurious to 
their healthy growth. 3. Roots possess the power of excre- 
ting certain matters which are in excess, or are unnecessary 
or injurious to them. 4. Roots have the power of modifyino- 
the fluids as they pass through them. — [Johnston. 

THE STALK OR STEM. 

The part of a plant which rises above the surface of the 
soil, which constitutes the principal axis, and is intermediate 
between the roots and branches, is called the stem. The 
direction of the stem is generally vertical, but in some plants 
it is obhque or horizontal. Stems, like roots, may be annual, 
biennial or 2^erennial. Plants are divided into herbs, shrubs, 
and trees, according to the size and duration of the stem. 

Herbs are plants with annual roots and annual stems, 
which do not become woody: such are the grasses, mints, 
most flowers, &c. 



II 



BOTANT. 109 

Shrubs have perennial, woody stems and roots, di\dded into 
numerous branches near the ground, and do not attain the size 
of trees : such are the alder, whortleberry, lilac and hawthorn. 

Trees have perennial, woody stems and roots, — do not 
branch off near the ground, and attain a great size : examples, 
elm, oak and pine. The distinguishiDg property of the stem 
is the production and development of buds. 

Buds are of two kinds, viz: the leaf-hid and the Jlower-bud. 

The leaf-bud consists of delicate layers of cellular tissue, 
or embrj^o leaves, covered by hardened crusty scales. 

The flow^er-bud consists of the rudiments of the new flower. 

There are several subordinate oro-ans, which are little more 
than appendages to the stem, and Avhich it is unnecessary 
to describe. 

STRUCTURE AND FUNCTIONS OF THE STEil. 

Plants are divided into exogenous and endogenous. 

The exogenous are those which grow by accumulation, or 
layers of matter from the outside. This class includes nearly 
all forest trees and most shrubs and herbaceous plants of 
temperate climates. 

The endogenous plants are those which grow from the inside, 
or by accretion of matter Avithin that already developed. Most 
of tlie bulbous plants of temperate regions, all the grasses and 
the palms, cane, &c., of tropical countries, are endogenous. 

The exogenous stem consists of bark, wood and pith. 

The pith is a light spongy substance, at the centi'e of the 
stem: it is composed of cellular tissue, and seems to ex- 
ercise its peculiar functions only during the earher growth 
of plants. — [Wood. 

The wood is composed of cylindrical or concentric layers, in- 
tersected by m.eduUaiy rays, Avliicli are those thin dense plates 
of wood dividing the " grains," and are large and easily seen 
in a piece of beech or oak wood which has been split. The 



110 



SCIENTIFIC AGRICULTURE. 



pith, togetlier witli tlie first layer wliich incloses it, are the 
rig. 17. product of the first year's growth ; 

one new layer is formed every suc- 
ceeding- year, — so that the number 
of rino-s or " grains " at the base of 
the stem indicate correctly the age 
of the tree. Each layer is composed 
of woody fibres, vasiform tissue and 
ducts. Fio-. 17. 



I 




[Fig. 17. 1, represents an exogenous 
stem of one yenr's growth ; a, pith ; b, 
bark; c, medullary rays; d, woody bun- 
dles of fibre ; 2, laticiferous vessels of the 
bark.] 

The outside, lighter colored lay- 
ers constitute the alhurnum or 
" sap wood ;" the brownish layers inside are harder than the 
sap wood, and are hence called the duramen. 

The bark forms the external covering or integuments of 
the stem and root. The bark consists of three distinct lay- 
ers ; the outside covering is called the epidcrmiSy — this layer 
is sometimes covered with a coating of gummy, oily or resinous 
matter. The middle layer is the cellular integimient; and 
the inner coat the liher. The two outer layers are of cellu- 
lar structure, while the inner one is both cellular and woody. 

The sap is carried by the vessels through the alburnum to 
the leaves, w^ith the vessels of which they communicate ; Avhile 
in the leaves, the sap undergoes some changes, (not well 
understood,) by means of the air and fight, by which it is 
converted into a fluid called latex. From the vessels of the 
under side of the leaf, it descends by the vessels of the inner 
bark ; part of it is carried imvards by the pores of the medul- 
lary rays, and diffused through the stem, while the remainder 
descends to the roots, and is distributed through them. Sap 
is milky, gumni}'-, saccharine, bitter, &c., in various plants. 



4 



BOTANY. 



Ill 



"The organs of assimilation at this period of their life, 
receive more nourishment than they employ in their own 
sustenance ; and when the formation of the woody substance 
has advanced to a certain extent, the expenditure of the 
nutriment, the supply of which still remains the same, takes 
a new direction and blossoms are produced." — [Liebig. 

At the end of spring a portion of the descending sap, which 
is now transformed into a nscid glutinous matter called cam- 
hiwn, is deposited between the liber and the wood, becomes 
organized into cells, and forms a new layer upon each. Soon 
afterwards, the new layers are pervaded by woody tubes and 
fibres, which commence at the leaves and grow downwards. 
" The number of layers in the bark and wood will always be 
equal." — [Wood.] The outer bark of young twigs seems to 
perform the same function as the leaves: in the cactus, sta- 
phelia, and other plants which produce no leaves, the bark 
must perform the same office as the leaves do in plants 
which produce them. — [Johnston. 

Fig. 18. 




e c 



dc Q da 



[Fig. 18. 3, horizontal section of an endogenous stem, exhibiting- the 
bundles of woody fibre, spiral vessels and ducts, irregularly disposed in 



112 



SCIENTIFIC AGRICULTURE. 



the cellular tissue . 5, a, a, cellular tissue ; b, spiral vessels on inner side 
of dotted ducts, c, c ; d, wood}' fibre on the exterior side ; 4, stem of 
three year's growth ; a, pith ; e, bark ; b, c, d, successive annual layers ; 
6 a, pith ; b, spiral vessels of the medullary sheath ; c, dotted ducts ; d, 
woody fibre ; e, bark.] 

The endogenous stem exhibits no distinction of bark, wood 
and pith, — and no concentric annual layers or grains. It is 
composed of cellular tissue, woody fibres, spiral vessels and 
ducts, the same as that of exogens. The cellular tissue exists 
equally in all parts of the plant; the rest are in bundles, im- 
bedded in the stem: "each bundle consists of one, or more 
ducts, with spiral vessels adjoining their inner side next to 
the centre of the stem, and woody fibres on the outside, as 
in the exooen. 

o 

" A new set of these bundles is formed annually, or oftener, 
proceeding from the leaves, and passing downwards in the 
central parts of the stem, where the cellular tissue is most 
abundant and soft. After descending awhile in this manner, 
they turn outwards and interlace themselves with those which 
wei'e previously formed." 



Cryptogamous or Flowerless Plants. 





i 



CHAPTER HI. 



STRUCTURE AND FUNCTIONS OF THE LEAF. 

The haf is an extension of the two outer layers of the bark 
expanded into a broad thin net work: leaves constitute the 
verdure of nearly all plants; their color is almost universally 
green, which color they derive from a substance called chloro- 
phylle, deposited just beneath the cuticle. Towards the end. 
of autumn, after the verdure of plants has matured, their color 
is changed to various hues, as yellow, orange, red, (fcc, by the 
action of oxj^gen on their elements. 

Deciduous leaves are those which fade and fall off at the 
end of autumn, annually. 
Evergreens are those which remain green throughout the year. 

Leaves are arranged in various Avays upon the stem and 
branches of plants : in some, as in the potato, they are scattered 
along the stem irregularly: in others, as the pea, they are 
alternate, or one above another on opposite sides of the stem: 
when two are against each other at the same joint or node, 
they are called ojyposite: when more than two are arranged 
in a circle at the same node, as in the meadow hly, they are 
verticillate : in the pepper and some others, they are arranged 
spirally around the stem. 

The prolongation of the leaf-stock, through the middle of 
the leaf, is called the midrib: the smaller diAdsions, or ribs, 
which radiate or go off from this, are called nerves. 



114 



SCIENTIFIC AGRICULTURE. 



The hair-like lines sent off from the midrib and nerves are 
called veins. This distinction is arbitrary, as there is no dif- 
ference in the structure or function. The various distributions 
of the veins have received distinctive names, and these are all 
included under the generic term venation. 

FORMS OF LEAVES. 

The forms of leaves have also subjected them to an 
arrangement under specific heads. The forms of leaves are 
said by De Candolle to depend upon the length of the i 
midrib and the relative length of the veins. f 

Orbicular leaves are roundish, as in the 
pyrola rotundifolia, or round leaf wintergreen, 
and nasturtion. Fig. 19. i 

Elliptical leaves, as their name ^^s- 20. 1 
implies, are elliptical or oval in 
form, as in the whortleberry and 




Avnitergreen. 



Fig. 20. 




Lanceolate leaves are long and tapering at the< 
point hke the blade of a lancet, as in the willow and peach. 
Fig. 21, a. 

Fig. 21. 




BOTANY. 



115 



Fig. 22. 



Fig. 23. 




Fig. 24. 



'ja? 



'mmK Th .,^f^ 



'■'-'!li!lilllP'','iriiK'iiii'ii";K^~ 






i!^ 



If 




rt b 



Cordate leaves are lieart-sliaped, as in the lilac and aster 
cordifolium. Fio-. 22. 

O 

Sagittate leaves have the form of an aiTow-head, as in 
the sagittaria. Fig. 23, a. 

Reniform leaves are kidney-shaped, as in the ^ald ginger 
and ground ivy. Fig. 24. 

Linear leaves are narrow, long and straight, as in the 
gTasses and grains. Fig. 21, c. 

Deltoid leaves are in the form of the Greek letter delta, 
or nearly triangular, as in the Lombardy poplar. Fig. 21, e. 

Acerose leaves are long, narrow and needle-shaped, and 
clustered together, as in the pine. Fig. 23, b. 

Piiinatified, or feather-cleft leaves, have deep clefts be- 
tween all their veins, separating the leaf into parallel segments, 
as in the lepidium. Fig. 25, d. 



lie 



SCIENTIFIC AGRICULTURE. 
Fig. 25. Fig 26. 





Fig. 27. 




Lyrate leaves have several deep rounded notches between 
their veins, as in the water-cress. Fig. 25, c. 

Connate leaves have the bases of opposite leaves united so 
as to appear hke one entire leaf, as in the boneset and sapo- 



naria. Fig. 26. 



Digittate leaves have narrow, deep clefts between the veins, 

with long segments radiating from the end of the leaf-stalk, as 

in the common hemp. Fig. 27. 
Fig. 28. 

Stellate leaves are arranged around 
the stem in such a manner as to form a 
star, as in the red hly. Fig. 28. 

Lohed leaves are deeply indented or 
cleft at their margins, so as to divide 
them into lobes, as in the liverwort. 
Fig. 29, a. 




BOTANY. 



117 



Sinuate leaves have tlieir margins divided by deep roundish 
clefts, as in the white oak. Fig. 29, b. 

Fig. 29. 




Emarginate leaves are irregidar, having but slight indenta- 
tions in the margin. Fig. 29, c. 

Tubulate leaves have the sides or maro-ins united so as to 
form a cup, as in the side-saddle and pitcher plant. Fig. 30. 

Fig. 30. 




Fig. 31. 




Compound leaves consist of 
several small leaves on separate 
leaf-stalks, and arranged along the 
opposite sides of the same stem, 
as in the hedysarum. Fig. 81. 

Ternate leaves. . . pig. 22. 
arise in threes from 
the same leaf-stalk. ,/ 
Fig. 32. V 

Biternate is a se- 
cond division by 
threes. 





118 



SCIENTIFIC AGRICULTURE. 




Leaves are opposite when placed at eqaul 
distances in pairs on opposite sides of the stem. 



Fio-. 33. 



These are the principal forms of leaves; 
still, many other names are given by botanists 
to the various modifications of these. Specific 
terms are employed also in describing the 
stem, margin, base, point and surfiices of leaves. 

There are also various appendages to the 
leaves, which have distinctive names, in sys- 
tematic works on botany. To describe all the 
minor points in the organography of plants^ 
would exceed our hmits ; and, besides, it would render this brief 
outUne of botany too complex to be interesting to the general 
reader. 

MINUTE STRUCTURE OF THE LEAF. 

The frame work of the leaf is an extension and expansion of 
the medidlary sheath, which is composed of woody fibre and 
vessels. The integument, or outer covering of the leaf, is 
the same as that of the bark, of which it is a continuation. 
. The cellular tissue peculiar to the leaf is called its paren- 
chyma. The parenchyma exists in two layers of cells, which 
differ somewhat in structure. Within the cells, and adhering 
to their walls, are the minute green particles of chlorophylley 
which give color to the leaf : the empty ,, 
spaces between the cells communicate 
with the external air by means of sto- 
mata, or mouths, which, in most plants, 
are found only on the lower surface. 

In all those plants whose leaves are 
vertical, as the iris, they are on both ^ 
[Fig. 34. Maornified sides equally : in the water hly, they I 

stomata, c, c] lower surface being in contact with the 




BOTANY. 



119 



water. The veins wliicli cany tlic latex, or nutritious fluid of 

the leaf, " having reached tlie edge of the leaf, double back 

upon themselves," spread througli the lower surface, and are 

ao-ain collected, and returned throuoh the leaf-stalk into the 

bark. 

Fig. 35. 




e e e e 

[Fig. 55 shows a mairnified section of the leaf of tlie Ii!y: the upper 
surface, a, consists of flattened cells of the ejiidermis, arranged in a 
single layer; beneath this, b, is the more compact part of the paren- 
chyma, consisting of a layer of oblong cells placed in snch a position 
that their longer axis is perpindicular to the leaf's surface. Next 
below is the parenchyma of the lower surface, c, composed of oblong 
cells arranged longitudinally, and so loosely compacted as to leave 
larger spaces between. Lastly, d, is the ej idermis of the lower surface, 
with stomata, e, e, opening into air chambers, f.] 



FUNCTIONS OF THE LEAF. 

The functions of the leaf are, exhalation, ah^orption, respl- 
ratlon, and digestion. The ultimate end of these functions is 
to produce the necessaiy changes on the crude sap brought 
up from the roots, and to convert it into the latex, which is the 
proper nutrition of the growing plant : this fluid is to the plant 
what the arterial blood is to the animal system. 

Exhalation in plants is the throwing ofi" of the excess of 
water in the sap, so as to leave it in a more concentrated form, 
and consequently better adapted to nutrition : exhalation takes 
place through the stomata, and is different from mere evapo- 
ration, Avhich depends upon the state of temperature and air. 
Exhalation is supposed to cease during darkness. 

Absoiytion is performed mainly by the roots, in nearly all 
plants : Avhen, however, these are defective or wanting, the leaf 



120 SCIENTIFIC AGRICULTURE. 

assumes the vicarious office of absorption. The invigorating 
effect of a shower of rain on the leaves of parched and wilted 
plants, is seen long before the water could have reached the 
roots and have been carried up to the leaves : this effect must 
be produced, therefore, by the absorption of moisture by the 
leaf This action takes place mostly from the lower surface, 
of the leaf. 

Hesjnratioii in plants consists, as in animals, in the absorp- ^ 
tion of oxygen from the air, and the giving off of carbonic' 
acid. It is performed mainly by the leaves, but is performed 
to some extent by other parts also: it continues without inter- 
mission by day as well as by night, during the life of the plant. 
Respiration is most active during the processes of germination 
and flowering: a constant supply of oxj'-gen, and the daily 
presence of light, are indispensible to the growth and vitality 
of the plant. 

Digestion comprises all those changes which the mineral, 
aqueous and gaseous matters undergo after entering the plant, 
until thev are assimilated and become a part cf the organism. 
" It consists in the decomposition of carbonic acid by tlie green 
tissues of the leaves, under tlie stimulus of the light, the fixa- 
tion of the solid carbon, and the evolution of pure oxygen," 

[Wood. 

INFLORESCENCE. 

Inflorescence is the term used to indicate the peculiar 
arrangement of flowers upon the stem and branches of plants; | 
also their successive development in different parts of the same ' 
plant. Flowers are said to be terminal and axillaiy, in regard 
to their position on the stem. 

Terminal flowers are placed at the end or summit of the 
branch or flower stalk. 

Axillary flovrers are placed in the angle formed by the 
branch or leaf-stalk, and the primary central stem, or larger 
lateral branches. 



I 



iJOTANY. 



121 



The lyeduRcle is tlio flower-stalk, or that part of the stem 
which is attached to and supports the flower: it may be 
simple or branching, and it may be entirely absent 



Fig. 35, 




[Fig. 36 shows a papilionaceous flower with its peduncles.] 

A scape is a flower-stalk, or peduncle, which springs imme- 
diately from the root, in those plants which are called stem- 
less, as the sarracenia, hyacjmthus, &c. 

A rackis is the main axis, or stem, of a compound pedun- 
cle, along which are arranged the flowers, as in the currant, 
grape, grasses, plantain, cic. 

A flower is said to be solitary, when a single terminal or 
axillary flower is developed, as in the erythronium and con- 
volvulus. The successive evolution of flowers is distinguished 
into ttt^o varieties, viz : the centripetal and centrifugal. 

In centripetal inflorescence^ the blooming of the flower com- 
mences at the circumference and proceeds towards the centre, 
as in the mustard, carrot, ttc. 

In centrifugal inflorescence, the blossoming commences at the 
terminal or central flower, and advances laterally to the circum- 
ference, as in the elder, pink and sweet-william. These two modes 
of inflorescence are sometimes combined in the same plant. 

There are several varieties of centripetal inflorescence, which 

are designated by specific terms; as the spike, raceme, amont, 

spadix, corvmb, umbel, head, panicle and thvrse. 

6 



122 



SCIENTIFIC AGRICULTURE. 



Of centrifugal inflorescence, there are also several varieties, 
as the cyme, fascicle, whorl, or verticil, &c. J 

Fig. 37. 




[Fig. 37 represents a head of oats showing an example of a panicled 
flower.] 

Tendrils. 




CHAPTER IV. 



GENERAL REMARKS. 

The dissemhiatioii of seeds is a subject not unworthy of 
allusiofi. It is known to botanists, that nearly all plants have 
particular localities to which they are indigenous. But, by 
various means, they have become more or less distributed over 
different and distant parts of the earth. Some seeds, as those 
of the thistle and dandelion, are furnished with a little plume 
or wing, by means of which they are wafted by winds to great 
distances, and thus sown in a soil and locality where the 
•species was never before known. Some seeds are furnished 
with hooks or burrs, by means of Avhich they attach themselves 
to the clotliing of men and animals : seeds are also eaten by 
animals and birds, carried to great distances, voided undigested 
and -without injury to their vitality, germinate wherever they 
are deposited. 

Many seeds are so protected by a thick dense pericarp, that 
they make long voyages, being carried along by the current 
of streams, or the ebbing and flowing of tides, until they reach 
a distant country, and perhaps even another continent, and 
there propagate and establish their species. They are carried 
also by ships and other conveyances engaged in commercial 
transportations, as well by accident as by design, for the 
purpose of cultivation. Many seeds retain their vitality after 
boiling, digestion in alcohol, and being buried in the earth for 



124 SCIENTIFIC AGRICULTURE. 

centuries. Dr. Lindley mentions a remarkable instance of the 
longevity of raspberry seeds, wbicb, as proven by cii-cum- 
stances, must have been 1,600 years old, and were found 
thirty feet below the surfece of the earth. Oily seeds are 
more hable to putrify and lose their vitality than others. 

A root was found in the hand of a mummy, which had been 
entombed 2,000 years ; the root was planted and watered, and 
there grew from it a beautiful dahlia. — [Lindsay's Travels. 

The blooming of flowers Vv^as thought, during the dark and 
middle ages, Avhen the human mind was blinded by the | 
grossest superstition, to be emblematical of something con- 
nected with religion : thus when the time of the blossoming 
of a flower fell on the birthday of a saint, or on the day of a 
martyrdom, that flower was consecrated or dedicated to such 
saint or martyr. 

Plants exhibit many phenomena which seem to be connec- 
ted with atmospheric conditions and changes : thus it is said 
a storm may be predicted by the folding or opening of certain 
flowers ; also that a clear sky, thunder, v/ind, (fee, may be fore- 
told by the various other phenomena observed to take place 
in the different organs of plants. Some plants are capable of 
cndurino- a hioh decrree of heat: those of the tropics sustain 
a temperature which would be intolerable to animals for a 
great length of time : others are found immersed in the waters 
of boiling springs, and in a state of thrifty vegetation. 

Every country exhibits a flora, or botanical character, pecu- 
liar to itself. The influence of lio-ht and heat on the irrowth 
of plants is seen to be powerful and important. In the polar 
regions, where almost perpetual winter reigns, the vegetation 
is rigid, scanty and stinted: the centre of the frigid zone, in 
fact, is totally destitute of vegetable life. After passing the 
arctic circle, we find a few species of mosses, lichens and ferns, 
and a few shrubs. The only country in this zone where the 
gTains can be successfully cultivated, is Lapland The tern- 



BOTANY. 125 

perate zone produces most species of useful nutrient plants, 
such as the grains, berries, fruits and grasses, as well as valu- 
able timber trees. The torrid zone produces every variety of 
vegetation from the equator to the poles: this variety depends 
upon the altitude at which they are found ; the low land pro- 
duces the most luscious fruits and stately trees, with a vast 
variety of flowers and spices. 

As vegetation ascends the mountain heights, even under 
the equator, it assimilates, according as the climate becomes 
less congenial, to that of the colder regions, in the same way 
as when receding from the equator towards the poles. Plants, 
hke animals, are Hable to various diseases: no inorganic body 
can be said to suffer from disease,— although they are subject 
to decomposition and disintegTation, they are not capable of 
diseased action, because destitute of vitahty, which is indispen- 
sible to such a process. Plants may become diseased from 
a deficiency or excess of food, air, hght, water, heat, — or from 
cold, noxious vapors, external injuries, insects, parasites and 
hereditary organic or functional debility. They are also 
liable to diseases pecuhar to old age and excessive action, in 
the same manner as animals. Thus they suffer from anemia* 
or want of fluids, hke aged persons: they sometimes labor 
under dropsy, from deficiency of light, — and from other causes 
they suffer and die from dry mortification* 

Lastly, plants are hable to disease and death from poisoning 
and contagion. The economical uses of plants are weU known, 
and require only a passing notice : forest trees, and some parts 
of other plants, are indispens ible in the arts: cereals, fruits 
and roots, are used as food for both man and beast : the grasses, 
hchens, mosses and herbs serve as food for animals: various 
plants, and the substances derived from them, are also used as 
medicines. Plants designed for medicinal purposes should be 
collected at a time when the whole vitahty and forces are not 

* Terms proposed by the author. 



126 SCIENTIFIC AGRICULTURE. 

engaged in the growth of the plant and maturity of the flower 
and seed: lierbs should be gathered soon after flowering, or 
when the seed is nearly ripened: roots, if annual, should be 
gathered after the stem and foliage are withered in autumn, 
or before the old root begins to decay in the spring: barks 
possess more strength if taken after the descent of the sap has 
ceased, and the cambium has become hardened into \yood and 
bark. 

Some remarks on the collection and preparation of plants 
for herbariums, and upon botanical analysis, classification and 
nomenclature, might be made: but they would be of httle 
service, as they would anticipate a step in the science which 
lies beyond the hmits of this treatise. 



PART IV. 



METEOHOLOGY. 



CHAPTER I. 

Meteorology is tlie science ■svliicli treats of all the various 
phenomena which take place in the atmosphere. " Under the 
term meteorology, it is now usual to include, not merely the 
accidental phenomena to which the name of meteor is applied, 
but every terrestrial as well as atmospherical phenomenon, 
whether accidental or permanent, depending on the action of 
heat, light, electricit}^, and magnetism. In this extended 
signification, meteorology comprehends climatology and the 
greater part of physical geography; and its object is to de- 
termine the diversified and incessantly changing influences 
of the four gi'eat agents of nature now named, on land, in 
the sea, and in the atmosphere." — [Brande. 

A meteor is any phenomenon of a transitory nature, which 
appears in the atmosphere. The various conditions and 
changes which take place in the air incessantly, with respect 
to heat, cold, moisture, dryness, (fee, are called weather. 
Observations have been made in all ages of the world upon 
these phenomena, in ordef to explain their causes and foretell 
the chano-es of weather. But there are so many conditions to 
be considered, and so many influences wliich probably can 



128 SCIENTIFIC AGRICULTURE. 

never be understood, that there is little certainty in all the 
theories and weather tables which have been formed. 
Although many of the meteorological phenomena are some- 
what well undersk)od in their individual nature, still, when 
they are combined, their operation is exceedingly complex, 
and the number of their changes almost infinite. 

Records of past changes of weather have long been kept, 
but it has been found by observation and comparison of the 
results of different seasons and years, that few data are 
obtained, on which to ground any prognostications of the 
future. Some indi^dduals have, by long and close observation, 
attained some apparent accuracy of judgment in relation to 
the phases of the weather; but their conclusions were not 
of a nature to be systemized and transmitted to posterity; 
so that, if any real attainment has been made in this way, 
it has always been lost with the observer. 

"The registers which are kept in different observatories; 
prove, contrary to popular behef, that the changes of weathei 
are in no way whatever dependent on the phases of the 
moon." Although the ever varying and endless changes of 
weather are all the necessary results of fixed laws, yet it 
is doubtful whether these laws will ever be sufficiently un- 
derstood to enable us to reduce our knowledge respecting 
them to demonstrative certainty. 

CLIMATE. 

Climate, in its most extended signification, embraces all the 
modifications of atmospherio temperature and conditions, and 
the principal causes on which they are dependent: besides 
temperature, it includes humidity, dryness, winds, barometrical 
conditions, purity of air, &c. The principal causes which tend 
to modify climate are, latitude, altitude, direction in which the 
sun's rays fall upon the earth, configuration and aspect of the 
land, its proximity and relation to the sea, direction of the 
wind, density of the atmosphere, number of rays of the sun 



4 



METEOROLOGY. 129 

which are absorbed, amount of vegetation, character of the 
soil, and state of agriculture. 

But among all these causes none have so important an 
influence on determining the climate of a country as latitude 
and altitude. The degrees of heat are not always equal for 
the same latitude; thus at Rome, in latitude 43° north, the 
mean temperature is the same as that of Raleigh, North 
Carolina, in latitude 36° north. 

To obtain the mean daily temperature correctly, we must 
observe the thermometer every hour during the tAventy-four, 
and divide the sum of the temperatures by the number of 
observations, viz: 24. If this mode is too laborious, it may be 
obtained sufficiently accurate by observing the thermometer at 
6 o'clock, A. M., 2, P. M., and 10, P. M., — adding together the 
sum of the observations and di\-iding the product by 3 : the 
quotient will, in both cases, be the mean temperati«ire. 

It is generally admitted at present, that both Europe and 
IsTorth America have undergone a gradual and permanent 
change of chmate. There can be no doubt that the temperate 
climates of Europe and North America v/ere once tropical: 
this inference is drawn from the fact that the entire remains of 
tropical plants, such as palms, lycapodiums, equisitums, &c., 
are found in these countries in a fossil state, and often in the 
position in which they grew. This conclusion is strengthened 
by the generic character of the shells and corals of the second- 
ary rocks, and also by the remains of such animals as live only 
in hot cUmates, viz : the elephant, rhinoceros, tiger, and several 
animals of the saurian tribe, &c. : there are also other evidences 
that the mean temperature of our climate and that of Europe 
Avere once much greater than at present. 

Lines passing through points on the surface of the earth at 
which the mean annual temperature is the same, are called 
isothermal lines. These lines do not pass round the earth in 
a direct course, like the parallels of latitude, but they vary so 
as to assume a tortuous direction, g* 



the 

4 



130 SCIENTIFIC AGRICULTURE. 

The isochimenal lines, or Hnes of equal cold, or equal | 
winter, vary much more than the lines of equal summer. 
The reason why latitude affects the temperature of a climate, 
is because it varies the obhquity of the sun's rays in relation to 
the earth. This, however, is not the cause of the difference in 
the length of day and night at different places. 

The following table from Miiller shows the length of the 
longest day for the different latitudes. 

Polar elevation. Length of longest day. 

0° 12 hours. 

16°44' 13 

30°48' 14 " 

49°22' 16 « 

63°23' 20 

66°32' 24 

67°23' 1 month. 

YS^SQ' 3 " 

90° 6 " 

Altitude has an important effect on determining the mean 
temperature on all places, whatever may be their latitude. 
The temperature diminishes from the surface upwards as far 
as man has ever ascended, and probably beyond this point to 
the very limit of the atmosphere. The interior of the earth is 
supposed to be yet in a fluid state from the effects of heat; 
the solid outside crust constituting only 1 4 part of its whole 
diameter: at 50 to 40 feet below the surface, invariable tem- 
perature prevails ; that is, there is always an equilibrium, so 
that the mercury in a thermometer would remain stationary 
at this depth, whatever might be the temperature above in 
the open air. This point would be at the surface if the tem- 
perature of the air was always the same. The increase of 
cold upwards from the earth is at the rate of 1° F. for every 
114 yards. The snoio line, or line of perpetual congelation, 
varies less in proportion to latitude than altitude ; thus it will 



METEOROLOGY. 131 

be seen by the table below, that this line is mucb lower at the 

equator than in higher latitudes in proportion. 

Table of Snow Lines from Muller 
Coast of Norway, 2,340 feet above sea level. 
Iceland, 3,042 " " " " 

Alps, 8,80^ " " « " 

Mi Etna, '9,441 " " " " 

Himmalayas, 14,625 « « " " 

Mexico, 14,625 « " « « 

Quito, 15,600 " « " " 

There are three reasons given by Dr. Brande, why the cold 
increases as we ascend, viz: 1. The absorption of the sun's 
rays iq the denser strata of the atmosphere near the surface 
of the earth. 2. Radiation of caloric from the earth. 3. The 
ascending current of air. 

Configuration of the land varies the climate of a country : 
a plain is hotter than an uneven surface, all other conditions 
being equal. The sand on the desert plains of Africa some- 
times attains a temperature of 122° F. The side of a moun- 
tain or hill which faces the sun, is warmer than the opposite 
side, for the plain reason that its rays strike upon it more 
vertically. 

Proximity or distance from the ocean is another cause 
which varies chmate. Small islands and peninsulas have 
milder winters and fresher summers than the interior of conti- 
nents in the same latitude. 

The refrigerating effect of winds blowing from the polar 
seas is felt in countries at great distances : the reverberation of 
v/inds amonrc mountains also increases the cold and heat of 
certain locahties. The other causes upon which climate is 
dependent, are considered in another place. The following 
table from Muller, shows the mean temperature of several 
different places. 



! 
132 SCIENTIFIC AGRICULTURE. 

Tahle showing the mean temperature of several places during 
several years, — part of one from Muller's Phys. and Mefy. 


Calcutta, 
Jamaica, 
^Madras, 


CD 

o 
•-^ 

Q 

8 
p- 


Melville Island, 

North Cape, 

St Petersburgh, 

Edinburgh 

Geneva, 

Vienna, 

LondoUjg 

Paris, 

Baltimore, 

Rome, 

Mexico, 

Algiers, 




i- 
o 


22 35 
17 50 
13 5 


-< CO 

o 

^ or 


■ry-,COi— 'rf^CO>4i-Cn4^4-^CrTOT— r^Ti, 
^-^Oi':oi— '<:c>ooi— 'oooscnoi— '4^2; 
^ o o 

S-^^^tOCni— 'CTtCOI— 'H-iOtCJt>— 'rf^^ 
p^-:rOi4^^TOi— 'CO to^:rCiO-T^ 


Latitude. 


88 26 
77 55W 
80 21 E 


1— ' 
GO 

OO 


1^11— '-<H 1—1 COCOtOl— 1 
lOOtO^TtOOOiClCiOCntO 

o 

C5 COOitO tOI— '^tOtOO 
CC .+^C0050COCn-^Ot05 - 




Longitude 
E.andW.of 
Greemvich. 


1—1 

bO to to Or to to 

CO O O O OO 00 

>{i- 00 <:o -T -q- 05 


Elevation 
above sea- 
level in feet. 


00 -J 00 
JO JO CO 
H-i " "to 


Ci 
CO 


OiO5CnOTOiC7»Ot>4^i4i'-C0C0 

j)^jojr>^^jDj^ o "<rao to i— • 

H-1 " "cO "* "co O H-i "co Oi "to H-* ^"--T 

Ox 




The whole 
year. 


^T ^T Ci 
i^ J3i j<r 
"rf^ "to "o 


Or 
00 


OTatrf^cocococococoi— 'toto 

J*^ Ox Ci jO GO JX) JO j(^ 00 Oi oo CD 

*^ "rf^ "bx "co " ""hf*. ~bo "to 00 "co 00 "to 




Winter. 


82,5 
78,7 
83,6 


05 


CiOiC7aTCr»^fKCn^t»>*^COtO 

_co jfii. j<r ^1— 'coi— 'ociCTTCoco 

CftCOOOOt— ' "f— I'co"^— ''ci'h-' 




S2)ring. 


00 00 oo 
J35 J-" _CO 

"to V "to 




-*fOi^:r^TOioOiOiOTC5:)rf^co 
^rf^ j^ j:o J^^ ^*^ j^a GO ►f^ OD o CO ^T 

CiCOtOOTOi"^~Col.o" 1o~^fi-'^-' 




Summer. 


00 00 -T 

l-i O CD- 
^ %• %• 


Ci 


•<r Oi Oi Or Or Ot Crt Or rfi- rfx CO 
jD^^H-iJUiJOj-'i— 'O00O>— 'O 
rf^ to o "ro "'-' "to " "to "►-' CO "o "^fi^ 




Autumn. 


18,4 Jan'y. 

24,4 

24,1 


"co 

> 


*-' ^-^ t— CO 

v.^ JO J-.T O J-i ZO J-* JD JO O Ol Crt 

O^ Co"tOOiOOOCirf^"co"coOlCO 

1 -5-^ 




Coldest 
month. 


29,9 May. 
27,7 July. 
31,3 June. 


to 


bOH-itOtOt— 'h-JtOh- II-JH-' 

>-^ J^ S^ ^ S^ J^>P S^ ^ S^ '^ Ox 

-r-TO OOGO'^TOOOH-'OO 

!>^ ^^ 

(SO. S ' ^^ 




Holiest 
month. 

1 




*;T!:\$-Q;r),''.v:, '•:''..a:: 






134 SCIENTIFIC AGRICULTURE. 

EXPLANATION OP THE CUT. 

This cut is designed to show the latitude and altitude at 
which some of the most important plants flourish in the 
greatest perfection. It shows also the latitude in which various 
winds prevail, — the latitude where there is httle or no rain, 
and also where there is almost constant rain. The scale of 
miles on the left hand of the cut shows the height of the 
mountains, the elevation at which plants grow on their sides, 
and the hne of perpetual snow. On the right hand are the 
degrees of latitude. The locality of plants, as shown by the 
table, are not perhaps strictly accurate in all cases; but they 
approximate correctness sufficiently near for all ordinary cal- 
culations. 



METEOROLOGY. 135 

INFLUENCE OF AGRICULTURE ON THE CLIMATE AND THE ANNUAL 

FALL OF RAIN. 

The question, whether the clearing- away of forests, and the 
labors of the agriculturist have had any influence in lessening 
the annual quantity of rain and the quantity of water in streams, 
as well as in modifying the chmate, is one of considerable 
interest and importance. The clearing away of forests, so as 
to allow of free evaporation of water from marshes, and per- 
mit the access of the sun's rays to the soil, most certainly has 
a tendency to equalize the distribution of heat, if it does not 
actually raise the mean annual temperature. The mean tem- 
perature of the whole earth, however, was much higher 
formerly than at present. The tillage of the soil, by rendering 
it loose, and exposing a greater surface to the action of heat 
and air, favors evaporation, and in this way makes a cold, wet 
soil, dry and warm. It also increases the capacity of the soil 
for heat, and favors nocturnal radiation and the formation of 
dew: but perhaps this fact goes about as far to sustain one 
side of the question as the other. 

It is a fact universally admitted by geologists, that the level 
of the waters of the earth have everywhere undergone a 
change. The instances are numerous, in which rivers, lakes, 
seas and marshes, have been greatly diminished or totally 
dried up; this may be one of those phenomena which is 
evident to all, but which is nevertheless difficult clearly to 
explain. Islands have risen out of the sea, coasts have been 
left dry by the receding of the waters, and the beds of large 
rivers have become dry arable soil. This has of course been 
in some instances owing to the actual elevation of portions of 
land by some subterranean force: and it is also true that 
portions have been submerged by similar causes. But these 
causes are insufficient to account for the general drying of 
streams and diminution of rains in cleared ao-ricultural dis- 
tricts. " In felling the trees which covered the crowns and 
slopes of mountains, men in all chmates seem to be bringing 



136 SCIENTIFIC AGRICULTURE. 

upon future generations two calamities at once, — a want of 
fuel and a scarcity of water." — [Humboldt. 

The rainy season is less regiilar in countries where the soil 
is dry and naked, than where it is moist and covered with 
dense forests or luxuriant vegetation. In some parts of South 
America, which are clothed Avith ancient and large forests, rain 
is falling almost incessantly: but in the same country, where 
there are w^ide extended plains and little vegetation, it seldom 
or never rains, Boussingault states, that when he was in 
Payta, in South America, the inhabitants informed him it had 
not rained there in seventeen years. The conclusions to which 
he arrived on this subject, part of them sustained also by 
Humboldt and Dr. Hitchcock, arc as follow^s : 

1. " That extensive destruction of forests lessens the quan- 
tity of running water in a country. 

2. " That it is impossible to say precisely whether this dimi- 
nution is due to a less mean annual quantity of rain, or to 
more active evaporation, or to these two effects combined. 

3. " That the Cj[uantity of running water does not appear to 
have suffered any diminution or change in countries which 
have known nothing of agricultural improvement. 

4. " That independent of preserving running streams, by 
opposing an obstacle to evaporation, forests economize and 
regulate their flow. 

5. " That agriculture established in a dry countr}^, not 
covered with forests, dissipates an additional portion of its 
runnino- water. 

6. " That clearings of forest land of limited extent may 
cause the disappearance of particular springs, without our 
being therefore authorised to conclude that the mean annual 
quantity of rain has been diminished. 

7. " That in assumino- the meteorolooical data collected in 
intertropical countries, it may be presumed that clearing off 
the forests does actually diminish the mean annual quantity 
of rain which falls." 



CHAPTER 11. 



RAIN. 



The philosophical principles upon which the phenomena of 
rain are immediately dependent, are not yet well settled : rain 
is supposed, however, by many of the best ^VTiters, to depend 
upon the action of electricity for its origin. All causes which 
have a tendency to reduce the temperature of the air, cause a 
precipitation of moisture. When the aqueous vapor which is 
held in suspension by the air becomes condensed by cold, the 
minute vesicles coalesce and form drops, which by their gra^aty 
descend through the air, which is no longer capable of sustain- 
ing them. 

The drops of rain are said to be from one twenty-fifth to 
one third of an inch in diameter : when they descend through 
a stratum of dry air, they are partly dissipated by evaporation. 
This accounts in part for the fact that there is less rain on 
plains than on mountains. 

The same latitudes have not the same quantity of rain: 
tliis, Hke climate, is modified by various local circumstances, — 
as altitude, proximity to the sea, direction and prevalence of 
winds, agricultural condition, forests, &c. The quantity of 
rain which falls during the year is gi-eater at the equator, and 
diminishes as we leave this point and approach the poles. 

The greatest annual depth of rain occurs at San Louis, in 
South Latitude 2^30', viz: 280 inches; the next gTeatest 



138 SCIENTIFIC AGRICULTURE. 



amount falls at Vera 


Cruz — ' 


vvliich is 2*78 


inches. 


The follow 1 


ing table shows the decrease 


of 


rain with the increase of lati- , j 


tude. 










? 


Grenada, 


12^ 


K 


Latitude, 


126 


inches. 


Calcutta, 


22^35' 




<( 


81 


« 


London, 


51°31' 




(( 


25 


« 



St. Petersburgh, 59°56' " 16 

It is not unusual in some countries, to see rain when the sky 
is clear and cloudless. The thickness of clouds between the 
upper and lower surfaces, varies from 100 feet to half a mile: 
their height above the earth varies from 2,000 to 23,000 feet or 
more. 

The quantity w^hich falls during the night and during the 
da}", varies at different places; in Europe more rain falls during 
the day than during the night time ; while in South Amei'ica 
more falls during night than during day. The mean quantity 
of rain is less as Ave ascend above the sea level : it is more in 
the same latitudes where the mean temperature is 08° F., 
than at any point above or below this. 

Rains become less periodical and regular as we leave the 
equator. The mean annual quantity of rain in Europe, between 
latitudes 35° and 50° north, (and probably the same would be 
nearly true of similar latitudes in the United States,) is from 
25 to 45 inches. 

The mean quantity, as shown by the report of the Regents 
of the University of New York to the Legislature, for the last 
ten or fifteen years, as measured at thirty different places in 
this state, is 35.84 inches. Of these various estimates, 43.65 
w^as the greatest number of inches, — wliich fell at " Erasmus 
Hall," Long Island: the smallest number was 28.14, which 
fell in St. Lawrence county. We see from tables in Bous- 
singault's work, that most falls in autumn and least in sprino*: 
we see also that most falls in July and least in March of any 
months in the year. 



METEOROLOGY. 139 

This table is from the record kept at the Rochester Collegiate 
Institute. 

Greatest annual amount of rain in any one year during the 

last fourteen years, ending with 1848, 39.99 inches. 

Least do. 25.46 " 

Greatest mean temperature of one year, 48°66' 

Least do. ----- - 43°7l' 

Highest, Juty, 1845, - - - - 102° 

Lowest, Feb., 1849, 10° below zero. 

Most rain in one month, Oct., 184G, 6.79 inches. 

Least, " " " " Jan., 1837, 0.16 

DEW AND FROST. 

All bodies in nature are constantly undergoing a change of 
temperature : hoAvever hot or cold a body may be, it is con- 
tinually giving out heat, either by radiation or by contact, or 
it is receiving and absorbing heat from other bodies. Upon 
the principle that heat tends to seek an equilibrium, by means 
of radiation and absorption among bodies, the production of 
dew and frost may be accounted for. 

During the absence of the sun, a great quantity of heat is 
dissipated from the surface of the earth by radiation : by this 
means, when the night is clear, the temperature is considerably 
lowered: when, however, tlie earth is overhung by a canopy 
of clouds, the}^ radiate in return, or reflect, and thus maintain 
an almost uniform temperature. When the clouds are absent, 
all the heat radiated by the earth is lost in the upper regions 
of space, and tlie surface is reduced in temperature many 
degrees below the atmosphere. 

" The stratum of air which lies in contact with the surface 
of the ground is then cooled by contact, and a portion of the 
watery vapor which it had possessed in the elas.tic form, is 
deposited as liquid water. If the temperature of the air be 
itself low, and the night very clear, the cooling may proceed 
so far that the drops of dew at the moment of their deposition 



140 SCIENTIFIC AGRICULTURE. 

shall be frozen, and thus form frost."— [Kane.] The fact is 
familiar to most observers, that dew and frost are formed only 
in clear starlight and still nights, — and then only on the 
surface of good radiators. 

The coohng of the earth's surface by the loss of radiant 
heat, is prevented by a covering of snow or any other sub- 
stance which intercepts its passage, and no dew or frost is 
formed. Thus plants may be protected against frost by 
covering them with a blanket or layer of straw : the same end 
may be attained by raising large fires by means of damp straw, 
brush, &c., so as to destroy the transparency of the air by a 
cloud of smoke and watery vapor. This mode is practiced by 
the Incas of South America, who seem to understand the 
conditions under which dew and frost are formed. When 
there is a current of air, there will be no condensation of 
watery vapor so as to form dew or frost; hence they are 
seldom or never seen on a windy night. 

In some parts of the world, as in sections of South America 
and Mexico, dews are so copious as to supply the place of 
rains. The cold ascribed by many persons to the hglit of the 
moon, is nothing but the consequence of nocturnal radiation. 
Mists, fogs, and clouds, are only floating vesicles of watery 
vapor, which obscure the transparency of the atmosphere; 
they differ only in the degree of their density. " A fog [says 
a celebrated naturalist,] is a cloud in which one is, — a cloud is 
a fog in which one is not." Fogs are not common in hot 
countries, — they rise to a small height, and are prevented by 
winds. In Peru dense fogs continue for half the year. Day 
fogs are volcanic ashes and vapors diffused through the air by 
wind. The appearances of clouds may be changed according 
to their height, density, distance, and the angles at wliich the 
sun's light strikes upon them, (fee. They are moved about 
and broken apart by winds, and assimie various and beautiful 
hues, according to the different colors of the sun's rays which 
they reflect. 



METEOROLOGY. 141 

Clouds, then, are merely floating, distant fogs, and are most 
frequently formed over some body of water or wet soil. 

SNOW. 

Snow is congealed Avater, wliich descends from tlie upper 
regions of the atmosphere. The precise conditions of atmos- 
phere requisite for its formation, or the manner in which it 
takes place, is not yet well understood. The most that is 
known respecting it, is in relation to the form of its flakes: 
these are stellate, and composed often of hexagonal prisms, 
arrano-ed at an anoie of 60°, from each of which others fre- 
quentl}^ shoot out at the same angle. The whiteness of snow 
is said to depend on the minuteness of its crystals. In some 
cases sirow presents no appearance of crystalization. 

Snow is often seen, in the arctic regions, both of a red and a 
green color. These colors are caused by the presence of an 
infinite number of microscopic plants and animalculae, which 
hve and propagate their species at a low temperature. These 
minute plants are composed of globules, varying in diameter 
from 1 to 3 0^0 of an inch : each globule is divided into seven 
or eight cells, filled with a liquid in which float numerous 
animalculae. The cells are originally red, but are changed to 
green by exposure to hght. — [Brocklesby. 

Snow recently fallen has a bulk ten or twelve times that of 
the water from which it is formed; while common ice has a 
bulk only about one-ninth greater than the water of which it 
is formed. The temperature of the air in which snow is 
formed must be below freezing, — that is, 32° Fah. ; and if it 
falls through a warmer temperature in its descent to the earth, 
it is melted, — hence there is no snow in warm weather, nor in 
the torrid zone, except on the summits of mountains wliich 
reach above the hue of perpetual congelation. It may there 
snow above and rain below. 

The snoio line, or line of perpetual snow, varies greatly in 
altitude, according to location and circumstances. On the 



142 



SCIENTIFIC AGRICULTURE. 



Himmalaya chain, according to Humboldt, the snow line on 
the south side is 4,400 feet below that on the north side; so 
that this hne cannot be depended upon as a point by which to 
estimate the altitude of mountains. 




[This figure, from Miiller, shows a few of the forms of snow flakes or 
crystals, all of which belong to the hexagonal system.] 

HAIL. 

Hail is a well known meteor, which occurs most commonly 
in spring and summer, and is often actompanied with thunder. 
It is foi-med by the congelation of rain or vapor in the upper 
regions of the atmosphere. Hail storms are of rare occurrence, 
and seldom continue more than a quarter of an hour. These 
storms occur most frequently in the summer, in the hottest 
part of the day; but rarely in the night. In France hail rods 
have been erected, with the view of preventing hail storms, — 
they have not^ however, proved effectual. 

Hail clouds always float lower than rain clouds. Hail stones 
appear to be composed of several spherules adhered together; 
those of the centre being soft, sometimes nearly fluid water, 
and those of the circumference sohd and opake. They are 
also occasionally laminated or radiated. Hail stones are some- 
times enormously large: the largest of which we have seen 
any account, according to Dr. Brande, measured 14 mches in 



METEOROLOGY. 14<. 

circumference, and weighed from 5 to 13 ounces. Many inge- 
nious speculations have been made, to account for the forma- 
tion of hail, but none of them sufficiently satisfactory to be 
entitled to implicit belief The most probable cause of this 
phenomenon now is, that " hail is produced by the mixture of 
exceedingly cold air with a body of hot and humid air." 

[Olmstead. 
Whether a cold wind comes suddenly from the regions of 
perpetual congelation, in contact with a body of hot air charged 
with vapor, blows suddenly into the regions of perpetual frost, 
and thus, by condensation of the vapor, produces hail, we can- 
not determine. It is sufficient for this theory, that hot moist 
air meets.with intensely cold air in any way whatever. 

LIGHTNING. 

" This is an electric phenomenon produced by the passage 
of electricity between one cloud and another, or between a 
cloud and the earth." The zigzag form of the flash, the fre- 
quency of its repetition, and the great length or extent of sky 
which it embraces, are not yet well understood or accounted 

for. 

The phenomena of lightning are best observed from the tops 
of mountains which extend above the clouds; from such a 
position the flashes have been observed to extend for several 
miles in length. The frequency of succession, and leng-th of 
the luminous streaks, are supposed to depend upon the imper- 
fect conducting power of the clouds and vapor between them. 

The question is now settled, that lightning rods, by con- 
ducting ofl:' the fluid, serve as a protection to buildings. The 
rod protects a circle, the diameter of which is four times the 
length it extends above the highest point of the building: 
hence the failures of lightning rods have been owing to their 
not extending sufficiently high. 

Lightning rods should be made of wrought iron, or copper, 
which is still better. 



144 SCIENTIFIC AGRICULTURE. 

It is said that thunder and lightning occur less frequently 
along the lines of the magnetic telegraph during rains, than 
before its erection. It is certain that the telegraph often col- 
lects and conducts off the electricity of the air and clouds. 

Spontaneous electricity, or St. Elmo's fire, is a blaze of blue 
electric flame often seen at sea, playing about the top of ships* 
masts, and also about spires of castles, and even upon rain and 
hail drops. 

THUNDER. 

The noise produced by the passage of lightning or electricity 
through the air, from one cloud to another, or from a cloud to 
the ground, is termed in common language, thunder. The 
loudness of thunder depends upon the magnitude and prox- 
imity of the explosion, the relative position of the clouds, the 
character of the surrounding country, and the position of the 
observer. 

The sharp crashing noise sometimes heard, is caused by 
lightning striking near us : the low rumbling noise is the effect 
of distant thunder : the rattling sound is occasioned by a quick 
succession of explosions from a highly charged cloud. The 
same species of snapping noise attends the discharge of sparks 
from the prime conductor of a charged electrical machine. 
" And when we consider how trifling a portion of electric 
matter is put in action bj^ the most powerful means of artifi- 
cial excitement, compared with the quantity stored up in a 
full charged thunder cloud, the discrepancy between the 
appalling crash of the one and the insignificant snap of the 
other, it will appear surprising that both should originate in 
the same cause." — [Brande. 

Lightning is the fight attendant upon electrical action, and 
thunder the noise which succeeds it: the difference in time 
between the two phenomena depends upon the distance of the 
explosion from the observer, allowing the velocity of sound to 
be 1,125 feet, and that of light about 200,000 miles in a 



METEOROLOGY. 145 

second of time. Tliunder storms are most frequent in the 
torrid zone, and diminish towards either pole. Thunder clouds 
may be positively or negatively electrified, or different parts of 
the same cloud may be in either state. 

Atmospherical electricity is stronger in winter than in sum- 
mer : it is also strong*est between 6 o'clock A. M. and 2 P. M., 
and weakest at about sunrise. Electricity originates from 
several difl^rent causes, viz: evaporation of impure water, — 
condensation of aqueous vapor, — evolution of gases from vege- 
tation,— friction, combustion, and various chemical processes, 
and by the physiological actions of animal bodies. 

We giv^e below an extract from the " Encyclopedia Brittani- 
ca," showing the various conditions under which electricity 
appears in the atmosphere. 

" 1. In regular thunder clouds. 

" 2. During fog T\'ith small rain. 

" 3. During a brisk snow or hail storm. 

" 4. During a smart shower on a hot day. 

" 5. During a shower on a cold da}^ 

" 6. In hot weather after wet days. 

" 7. In hot weather after dry days. 

" 8. In clear and frosty weather. 

" 9. In clear warm weather. 
" 10. During a cloudy sky. 
"11. During a mottled sky. 
" 1 2. In sultry weather with light hazy clouds. 
" 1 3. In cold damp nights. 

" 14. During a north-west wind, which produces a sensation 
of dryness and coldness, not indicated by the thermometer." 

WINDS. 

Wind is air put in motion. Rarefaction of one portion of 
the atmosphere by heat, and condensation of another portion 
by cold, are the principal causes of wind. Some local causes 

7 



14(3 SCIENTIFIC AGRICXTLTURE. 

of limited extent may produce wind, — such as large fires, &c. ; 
but these winds are limited to the locality where they origi- 
nate. There is no known cause, besides heat and cold, which 
is capable of producing any general or extensive cuiTent in the 
air. 

A wind may be merely relative or apparent, and proceed 
from the passage of the observer through the air, as by a 
steam car or balloon. If the speed of his vehicle be twenty 
miles an hour, he feels a current of air equal in velocity to his 
own ; the wind appears to blow at that rate. The direction of 
winds may be modified by various causes : when two or more 
currents meet from different directions, the general direction 
will be a resultant one, the consequence of the several forces, 
as in the case of trade winds. 

Winds have received various distinctive appellations, accord- 
ing to the phenomena which they present : thus we have the 
trade winds, the land and sea, breezes, the harmattan, the 
monsoon, the simoon, the sirocco, whirlwind, hurricane, and 
tornado. A brief description only of each of these varieties 
can here be given. 

Land and sea breezes. — These winds prevail mostly among 
the islands of the torrid zone ; but more or less in all maritime 
countries. They are mild, balmy breezes, which blow towards 
the shores during the day, and from off the land towards the 
sea during the night time. Their phenomena is explained as 
follows : during the day the land becomes heated by the rays 
of the sun, — the heat of the ground rarifies the air, which 
consequently rises to the higher regions, while the cold air 
from off the ocean rushes in to supply its place ; thus producing 
a breeze inland as long as the sun continues to warm the earth. 
This is called the sea breeze. 

During the absence of the sun, the earth, which radiates its 
accumulated heat faster than the sea, becomes cooler, and the 
direction of the breeze is changed : the air from off the ocean 



METEOROLOGY. 147 

rises, while the colder air from the land rushes in to supply its 
place, just as in the case of the sea breeze. This night wind 
which blows off the land is called the land hreeze. As the 
central part of an island becomes warmer than its shores, the 
breeze will be the strongest in the midland : " its current mil 
also be performed in a constant gyration; so that the air which 
flows in upon the land by day, rises, flows out above, and 
returns again in the same current : and the process is similar 
by night, only the current is reversed." At the time when a 
perfect equilibrium exists between the temperature of the land 
and sea, the wind ceases, and there is for a time a dead calm. 

Trade winds are produced by the same causes operating 
upon a larger scale, and the revolution of the earth on its own 
axis. These are tropical winds, which prevail only within the 
limit of about 30° each side of the equator. Their general 
course on the north side of the equator, is from north-east to 
south-west, — and on the south side, from south-east to north- 
west The upward current of the air at the equator, in conse- 
quence of its higher temperature, causes the colder air to rush 
in from the north and south towards the point of greater rare- 
faction ; this produces the northward and southward currents. 
These currents have now a westerly tendency given them by 
the diurnal rotation of the earth on its axis towaixis the east; 
thus producing their general directions as above described- 
When not changed by local causes, their direction is the same 
throughout the year : but however they may be modified, they 
always blow towards the point of greatest rarefaction, and 
receive a relative motion from the earth's diurnal revolution. 
Their velocity is greatest at the equator, where the earth's 
motion is the most rapid, and diminishes towards the poles in 
proportion as the circumference of the earth diminishes, and 
the motion is less rapid. 

The harmattan wind is a periodical easterly wind, wliich 
blows irregularly in Africa: it occurs three or four times 



148 SCIENTIFIC AGRICULTURE. 

yearly, and continues for a longer or shorter period, according 
to circumstances. It blows with only a moderate velocity, 
is peculiarly dry and unpleasant : it is attended by a haziness 
of the atmosphere, which often obscures the sun most of the 
day. During this wind there is no moisture in the air, and no 
dew or fog; vegetation becomes parched, and droops. Not- 
withstanding the depressing- and disagreeable effects of the 
harmattan, it is said to be a salubrious wind. 

Monsoons are a modification of the trade winds, which occur 
mostly in the Indian ocean, and north of 10° south latitude. 
The south-east winds blow from April to October, and are 
frequently attended by rain : from October to April they blow 
from the north-east, and are dry. The change from one 
monsoon to another is usualfy attended by violent storms. 

The si?noon is a hot pestilential wind, which, during certain 
seasons of the year, blows northward from the deserts of Africa 
and Arabia. This wind, after being modified by passing over 
the Mediterranean sea, is called, in the south of Italy, the 
sirocco; its poisonous effects are supposed to depend on its 
dryness. 

Whirhoinds are such as have a rapid gyratoiy as well as 
progressive motion. Hurricanes are generally whirlwinds con- 
fined to a narrow path, v,dth a forward motion, sometimes not 
exceedino- fifteen miles an hour. 

A wind which moves at the rate of 4 or 5 miles an hour is 
called a gentle Ireeze; when its velocity is 15 or 20 miles an 
hour, it is a gcde; when 30 to 40 miles an hour, a high wind ; 
and when 100 miles an hour, a hurricane or tornado. Hurri- 
canes are more frequent on the shores of China and the Indies 
than in any other part of the world. 



CHAPTER HI. 



VARIOUS ^RIAL PHENOMENA. 

Aurora Borealis. 

m 

"This is a luminous meteor usually appearing in the 
northern part of the sky, and presenting a hght somewhat re- 
sembling the dawn or break of day." The aurora exliibits 
such a variety of forms at different times, that no general 
description can give any definite idea of its appearance; this, 
however, may be easily attained by observation of the meteor 
itself. It appears to be a horizontal cloud extending towards 
the east and west, and rising a few degrees above the horizon. 
The lower part of the cloud is often darkish, and the upper 
part luminous and wliitish : from this part, streams or columns 
of hght shoot upwards with an unsteady, wave-like motion, 
reacliing sometimes to the zenith, and at others only a few 
degrees above the horizon. 

The color of the aurora is various,— ■being sometimes red, 
green, yellow, rosy and crimson. A rusthng or crackhng 
noise is said to proceed from it, by observers in high north- 
ern latitudes, — this is doubtful. This meteor occurs more 
frequently in winter than in summer. 

The " Northern Lights " usually appear two or three hours, 
or soon after sunset, and continue a few hours, and occasionally 
the whole night : they also sometimes appear for several sue- 



150 SCIENTIFIC AGRICULTURE. 

cessive niglits, but are rarely seen after midnight or in tlie 
morning. — [Brande.] Tliey often succeed a change of weather 
from heat and rain to cold and clear. They are sometimes 
tinged with green or orange, but more commonly with various j 
shades of red. The aurora is sometimes seen in tlie southern j 
hemisphere. The mean height of the luminous sheet lias been | 
variously estimated at from 100 to 400 miles, No satisfactory j 
explanation of this phenomenon has yet been given ; many ' 
ingenious theories have been proposed, but as we have not 
space to detail them for the gratification of the curious, Ave 
must refer them to larger and more scientific treatises. The 
probable cause, however, is electricity. 

I(/nis fatuus, or " Will o' the Wisp.'" 

This is a nocturnal light, commonly known in this country 
by the name of '■^ Jack- Lantern:" it is seen floating over 
marshy grounds, moors, grave yards, and along the margins 
of rivers, and sometimes has a progressive motion, which is 
probably given it by the passing breezes. The origin and 
nature of this meteor have been the subject of many super- | 
stitious theories and absurd speculations; it has often been 
ascribed to supernatural causes. The most probable expla- 
nation of it is that given by Muller: he supposes it to be 
hydrogen gas which is mixed with phosphorus; and that ^ 
consequently it is notliing more than a phosphorescent light. * 

A Halo, 

Is a luminous circle, usually of various and beautiful hues, 
surroundino- the sun or moon durino- certain conditions of the 
-atmosphere. There are two kinds of halo, depending upon 
different physical causes. The first are small, their diameter \ 
according to Dr. Brande, not exceeding from 5° to 10°, and 
composed of three or more concentric rings of different colors. 
*' These are usually called coronce; and they appear cither ' 



METEOROLOGY. 151 

when a small quantity of aqueous yapor is diffused tlirougli 
the atmosphere, or when light fleecy clouds pass over the sun 
or moon." The second kind consists of a single luminous 
circle whose diameter is about 45°. 

A halo of the moon is usually a white circle with its inner 
edge sometimes tinged with pale red. There is much ti-uth 
in the remark, that a dense halo close to the moon portends 
rain. Lunar halos are most frequent, because the sun's rays 
are too dazzlino- to admit of their beino- seen. The most 
probable cause of this phenomenon is that it depends on the 
refraction of light in passing through small transparent prisms 
of ice, floating in the higher regions of the atmosphere, 

AntheUa are coronas seen by reflection Avhen the observer 
stands with his back toAvards the sun: sometimes a number 
of coronas of various colors are seen at the same time. 

Parhelia. 

Parhelia, or mock suns, consist of the simultaneous appear- 
ance of several images of the true sun. They are at the same 
heio-ht above the horizon as the sun, and are connected bv a 
horizontal circle, which is sometimes colored, but usually white. 
The cause of these suns is not satisfactorily explained: they 
are supposed, however, to depend in some way upon the reflec- 
tion and refraction of the sun's rays. There may be parhelia 
without rings, and rings without parhelia. They never appear 
in an unclouded sky, — sometimes occur opposite to the sun. 

Paraselence are luminous rino-s seen about the moon : mock 
moons, or images of the moon, seen by reflection, are also 
called paraselena\ 

Fire Balls. 

These' are " luminous bodies which suddenly appear in the 
sky, usually at a great height above the earth, and shoot 



152 SCIENTIFIC AGRICULTURE. 

through the heavens ^ith immense velocity, and are sometimes 
accompanied by the fall of an ^roHte." Various hypotheses 
have been proposed to account for these meteors: hmit does 
not admit of a detail of these opinions; and it is perhaps suffi- 
cient to say, that the true explanation of this phenomenon has 
not, so far as we can ascertain, been given. 

i 
Rainbow, ^^^^^ \ 

This weU known and beautiful meteor consists of tw^^? 
centric arches, formed of the colors of the solar spectrum. It 
is caused by the refraction and reflection of the sun's rays 
while falling on drops of rain. The size of a rainbow depends 
upon the height of the sun above the horizon. Inverted bows 
are sometimes seen on the ground; they are formed by the 
rays of the sun falHng on the drops of dew or rain which are 
suspended from the top of grass, or from spider's webs; they 
are also seen about waterfalls and sliip masts, forming a perfect 
circle. Lunar rainbows are sometimes seen in the night time; 
biit their colors are faint and indistinct. In order to see a 
rainbow, we must face a cloud and turn our back to the sun 
or moon. The philosophical explanation of rainbows will be , 
found m works on natural philosophy and meteorology. 

Mirage. \ 

^ Mirage is an optical illusion often obseiwed at sea, especially 
in high latitudes; it sometimes also appears on the land, par- 
ticularly in Egypt and Persia; it is seen also on the margins 
of rivers and lakes. It consists in the appearance in the air 
over the surface of the sea, of multiphed images of objects on 
the surroundino- coast. 

"It arises from unequal refraction in the lower strata of the 
atmosphere, and causes remote objects to be seen double, as if 
suspended in the air." These imag-es are sometimes inverted I 
ships, whale fisheries, and other objects, are sometimes descried 



METEOROLOGY. 153 

by means of mirage at considerable distances. The matbe- 
matical theory of this phenomenon will be found in works on 
optics, &c. 

Shooting Stars. 

Tliese are common and well known meteors, some of which 
resemble fire balls in every respect. We shall not attempt 
any description or explanation of them, as their origin and 
nature are involved in great obscurity and uncertainty. 

trollies, or Meteorites. 

These are mineral masses which fall to the earth apparently 
from the upper regions of the atmosphere. They Lave a dark 
or blackish color externally and a gTayish hue internally. 
They have a specific gravity more than three times that of 
water : chemical analysis of one specimen shows its constituent 
elements to be, iron, sulphur, silex, nickel, magnesia, and 
sometimes chromium. These meteors have been supposed to 
come from volcanoes in the moon: but there is still great 
obscurity hanging about the whole subject. 

Their height above the earth is from 18 to 80 miles; they 
move with the astonishing velocity of 300 to 1200 miles per 
minute. The most probable explanation of their origin is that 
given by Prof Clapp, of Yale College. 

He supposes them to be terrestrial comets revolving about 

the earth: the heat which attends them is supposed to Le 

caused by the condension of the air by their rapid passage, 

and the explosions by the expansion of gases, by the heat 

thus produced. 

Color of the Sky. 

The general color of the unclouded sky is azure or blue : 
this is explained on the supposition that the particles of the 
atmosphere, when illuminated, reflect mostly the blue rays. 
Whenever the prevailing color of the sky is anything but a 



154 SCIENTIFIC AGRICULTURE. | 

pure blue, it is discolored by smoke, vapor and clouds; the 
more dense these clouds, the nearer the color of the sky 
approaches to black. The deep red of the morning and | 
evening sky is explained by supposing the atmosphere permits | 
only the red and yellow rays to pass, and reflects the blue 
rays. — [Miiller. 

The fiery red of morning is caused by an excess of moisture, 
which, notwithstanding * the tendency of the sun's rays to 
disperse it, forms clouds in the atmosphere, and hence indi- 
cates rain. A gray sky at morning and a red sky at evening, 
on the contrary, foretell fine weather. The various other 
beautiful hues which tint the sky and fringe the massive clouds, • 
so as to produce all the varied gorgeous drapery of the 
heavens, are caused by the absorption, refraction and reflection 
of the diflerent rays of the solar spectrum. 

Twilight. 

Twilight is the diminished light of day, which is seen from 
the setting of the sun on its sinking below the western hori- 
zon, till the last faint gleaming of day has disappeared. The 
time at which twilight begins and ends, is altogether arbitrar}'', 
and must depend very much on the acuteness of the vision of 
the observer. It has been said to commence at the moment 
of sunset, and terminate when the fii'st small stars are visible. 
Twilight is short in countries having a pure sky : in Chili, it 
lasts only a few minutes. In high latitudes it is of longer 
duration, on account of the sun's orbit being much inclined to 
the horizon. In countries lying in the vicinity of 50° of 
latitude, twilight continues until the sun has descended from 
15° to 20° below the horizon. 

The moon's light is only the reflected light of the sun, and 
is estimated to be, when in its greatest intensity, only ^^^^^ part 
as much as the light of that vast luminary. 



PART V. 

AGRICULTURE, 



CHAPTER I. 



rORMATION AND ELEMENTS OF SOILS. 

The soil is composed of disintegrated rocks, animal and 
vegetable matters ; most soils are made up of successive layers 
of fine sand and organic matters, loam, fine gravel, clay, coarse 
gravel, and occasional masses of rock of various sizes. Various 
causes have concurred to produce the alluvial deposit on the 
surface of the earth, which must ultimately have been formed 
entirely of the rocks which constitute the solid basis and 
principal bulk of the globe. 

The running water of rivers and the great ocean current 
which sweeps across the earth, had denuded the rocks wliich 
it washed in its course from the high lands to the plains and 
valleys : in this way, ra\ines have been excavated, valleys filled 
up, and vast level plains formed. The floods formed by rains, 
and the torrents resulting from melted snow and ice, which 
flow down the mountain's sides, wash away all loose matters, 
and often undermine and tear away fragments of rock : these 



156 SCIENTIFIC AGRICULTURE. 

are swept along by the impetuous stream, their corners worn 
oflF, and they, together with the finer particles, are deposited 
on the plains or in the valleys, in the form of sand, gravel and 
" boulders." 

The action of the air contributes powerfully to the decom- 
position and crumbling of rocks. Water, also, which falls into 
the cleavage or crevices of rocks, and becomes frozen, often 
cleaves large masses asunder by its expansion in passing into 
ice ; these masses are again subdivided in the same manner, 
until entire hills of marble, slate, and other rocks, are com- 
pletely pulverized. The affinity of the gases of the air and 
water for these elements of the various rocks produce the same 
efl'ect. The combined action of ice and water in transporting 
masses of rock is another powerful agency in the formation 
and distribution of soils. Immense blocks of rock are fre- 
quently frozen into ice, which is subsequently broken up and 
floated by streams and freshets to great distances from their 
original locaHty; these, in process of time, become pulverized, 
and add their elements to the soil. 

The action of fire in volcanic districts produces immense- 
effects in changing the character of rocks, levehng hills, and 
filling up valleys with ashes and lava; so vast is the quantity 
sometimes thro-svn out at a single eruption, that the whole 
countiy for many miles around is covered with the melted 
rocks, scoria, ashes and cinders. 

In this way Pompeii, Herculaneum, and Stabia were inhumed 
A. D. 79, by a single eruption of Vesuvius. Whole strata of 
rocks are sometimes broken up by earthquakes, and are after- 
wards disintegrated and mingled with the soil. The agency 
of winds in wafting fine particles of allu\aum and sand has in 
tnany places entirely changed the character of the soil; in 
some places vast barren plains have been formed, " dunes " or 
sand hills raised, fertile fields stript of alluvium, and others 
covered by sand containing no other elements of a fertile soil. 



M 



SCIENTIFIC AGRICULTURE. 157 

It Is apparent now, that the soil bears no necessary resem* 
blance in all cases to the rocks on which it hes, except when 
derived directly from them ; then it partakes of their nature. 

After the surface of rocks has by these agencies become 
sufficiently pulverized and decomposed to form a thin layer of 
soil, hcliens and mosses succeed in fixing their roots in it, 
causing at the same time further disintegration of the rocks, 
and increase of the soil by their annual decay. When the 
soil becomes in this way of sufficient depth and fertihty to 
nourish other, larger and more perfect species of plants, vegeta- 
tion becomes more abundant: the decay of this, together with 
the organic and earthy matters of animals, which are returned 
to the soil; combined with the art and industiy of man, — a 
soil sufficiently deep and fertile for successful cultivation, is in 
process of time produced. 

A general knowledge of the rocks, metals and earths, is of 
great value to the agriculturist, in enabhng him, by the indi- 
cations which they afford, to discover springs, mineral waters, 
ores, mines of coal or metal, marl, Hme, valuable stones, &c. ; 
and also to direct him to the best locations for lime kilns, glass 
houses, brick kilns, potteries, foundries, salt works, bath houses 
and stone quarries. Modern chemistry has shown that almost 
every substance is a compound of several others, — and future 
experiment may yet show us the compound nature of many 
bodies which are now considered elementar}^ There would be 
little difficulty in determining the character of any soil, had we 
only to consider the constitution of the rock from which it Wc'ta 
originally derived. 

But, during the lapse of ages, the various causes which have 
been in operation have so changed them that their primitive 
character has almost disappeared, and they must be considered 
in their present actual conditions. Arable soils consist mainly 
of silex and alumina, with some lime, iron, sodium, potassium, 



168 SCIENTIFIC AGRICULTURE. 

manganese, magnesia, animal and vegetable remains in various 
proportions and different stages of decomposition. The ele- 
ments of tlie soil must exist in different proportions, in order 
to render them available for agricultural purposes. 



CHAPTER 11. 



METALS, METALLOIDS, AND ORGANIC ELEMENTS OF SOILS. 

SILICON.* 

Silicon is one of the most abundant and widely distributed 
substances, constituting probably one sixth of the entire mineral 
weight of the globe. It is never found pure or in an uncom- 
bined state, but always combined with oxygen, forming oxide 
of silicon, or silicic acid. The vast mountains of granite, gneiss, 
porphyry and sandstone, — mica, feldspar, crystal quartz, nearly 
all precious stones, the sands of the sea shore and desert, and 
all stones that emit sparks on being struck by steel, are mainly 
silicon. 

It is contained in a crystahne state in the outside bark of 
many plants, particularly in cane, bamboos and the grasses. It 
is with difficulty separated from its oxygen, — but when sepa- 
rated and pure, it is a fine whitish powder, destitute of taste 
or odor: it undergoes no change, except becoming darker and 
denser, by any common degree of heat, but melts before the 
blow pipe into colorless glass ; it has no affinity for pure water, 
so that it is not dissolved in it in the smallest degree ; it absorbs 
water slowly, and allows it to escape easily. It is neither dis- 

* Recent investigations appear to show that silicon is neither a 
metal nor a metalloid. 



160 SCIENTIFIC AGRICULTURE. 

solved nor acted upon by an}^ acid except the fluoric, — with 
which it unites and forms a fluoride of silicon. 

The equivalent number of silicon is 22.22, — ^its specific 
gravity 2.66. The fixed alkahes easily unite Avitli silicon, and 
form silicates, as the silicate of potash, lime, &c. It forms an 
important ingredient in porcelain, glass, and the enamel or 
glazing of stone ware. The salts of silicon are not numerous : 
they are all insoluble in water, (according to Prof Johnston,) 
except those of potash and soda. 

As silicon is so important an element in plants, and so inva- 
riably present in all productive soils, a knowledge of its chemi- 
cal character, and the best means of rendering it available to 
the roots of growing vegetation, is indispensible. 

ALUMINUM. 

This metallic earth is found in greater abundance in nature 
than Unie, being one of the principal ingredients in nearly all 
rocks, except the purest hmestone ; it is the principal element 
of clay, and exists largely in garnet, albite and mica : it is found 
also in the ashes of most plants. In its native state it is usually 
found in combination with silica, and sometimes with sulphuric 
or phosphoric acid ; it is also found nearly pure, or uncombined 
in the ruby and sapphire, two beautiful precious stones. 
Alumina is an oxide, and the only one known of the earth 
aluminum : it is white, tasteless and inodorous ; its equivalent 
number is 13.7. 

It dissolves in acids and in solutions of caustic alkahes ; it 
has a strong tendency to unite with organic matters, and has 
also a greater affinity for water than any of the other elemen- 
tary earths. When mixed with sihca in the proportion to 
form clay, it is easily molded into any form, as in stone and 
earthen ware : it loses part of its tenacity by fire, — hence the 
benefit of burning clay soils. Alum is a salt formed by the 
union of potash, alumina and sulphuric acid, — this salt is 



SCIENTIFIC AGRICULTURE. 161 

extensively used as a mordant in calico printing. Alumina is 
supposed to contribute but little to the nourishment of plants : 
it is said by Liebig to be an absorbent of ammonia: this, 
however, is doubted by Prof. Johnston. Its principal agency 
as an element of soils is of a mechanical kind. The salts of 
alumina are few; they have not been sufficiently tested as 
fertilizers to determine precisely their value in this respect; 
Sprengel considers them highly deser\ing of trial in practical 
agriculture. 

MANGANESE. 

This metal is diffused widely through nature, although not 
in great abundance: it is found mostly in the mineral, — but 
traces of it also exist in the animal and vegetable kingdoms. 
It has a very strong affinity for oxygen, and is therefore with 
difficulty reduced from its oxides and ores, — which, however, 
may be done by a long continued and intense heat. 

It is hard, brittle, granular, gTayish white, and has a specific 
gravity of 8 : it is very infusible, soon tarnishes by the absorp- 
tion of oxygen, and after a while falls into a black powder. 
There are several oxides, two acids, and many salts of manga- 
nese, some of which are soluble and others insoluble in water. 
It is used in the arts, and is probably a necessary ingredient 
in soils. Its equivalent is 27.67. 

IRON. 

This is the most important of all the metals and is the most 
extensively distributed over the earth. It is sometimes found 
in loose blocks of pure metal on the surface ; but mostly in 
veins and mines, combined with sulphur, forming a gold 
colored ore, called sulphuret of iron, — and with oxygen in the 
form of the black and red oxides: it is also extensively com- 
bined with carbonic acid, constituting the clay iron ore. Native 

arsenites, phosphates, sulphates and other salts have been 
found. 



162 SCIENTIFIC AGRICULTURE. 

Nearly all reddish soils and stones are colored by oxide of 
iron. Pure iron is bluish white, brilliant, malleable and ductile, 
the strongest of all metals, and has a specific gravity of 7.8; 
its equivalent is 27.14. 

Iron oxidizes readily when in contact with moisture, and 
also by heat. Only two of the oxides are of any interest to 
the ao-riculturist, \\z. : the black and the red. The black oxide 
rarely occurs in the soil, except in combination with some acid ; 
and this, when exposed to the air, absorbs oxygen and changes 
to the red oxide. When the black oxide or sulphate is present 
in moist boggy soils, it proves injurious to vegetation : the red 
is less injurious. Both are insoluble in pure water, and both 
are soluble in acids. The red oxide is said to absorb ammonia 
from the atmosphere, and by thus bringing it within the reach 
of plants, it is in this way useful, when the soil contains any 
considerable quantity. 

A red soil containing m^uch iron should be turned over fre- 
quently, so as to keep it pervious to the air; and, according to 
Johnston, such soil " may occasionally be summer fallowed ■\;v-ith 
advantage, in order that the oxide may absorb from the mr 
those volatile substances which are likely to prove beneficial 
to the growth of future crops." 

The sulphate of iron (green vitriol ) is often found in soils, 
particularly in bogs, and marshy places, and it is said to be 
very injurious to vegetation ; these effects are counteracted by 
lime, marl, and plaster, which decompose the sulphate and 
unite with the sulphuric acid and form gypsum. In this way 
it is beneficial to soils containing hme, and may be used as a 
manure. Iron is found in the ashes of nearly all plants, and 
to a small extent in animal bodies. It is probable that some 
of the soluble salts of iron are requisite to the growth of most 
plants. 

A spring has recently been found at Oak Orchard, in Genes- 
see County, N. Y., which contains a large per cent, of sulphate 



SCIENTIFIC AGRICULTURE. 163 

of iron, and also free sulphuric acid. The locality is marshy 
and the soil apparently unproductive : the water is highly 
medicinal. 

SODIUM. 

Sodium exists in vast quantities, and is widely diffused 
throuo'h nature: it is found combined with chlorine, formino* 
common salt, of which great quantities are found in Poland, 
England and elsewhere. It is the principal saline ingredient 
in the waters of salt lakes and the ocean. It is found in many 
minerals, most plants, and in all the animal fluids. Sodium 
is found in vast quantities in South America in the form of a 
nitrate. 

The pure metal sodium is lighter than water, its specific 
gravity being 0.972; its equivalent number is 23.3. It is a 
silvery white metal, resembling potassium closely in its appear- 
ance. The compounds of sodium are numerous and important. 
This metal is soft at common temperatures, melts at 194° F., 
and oxidizes rapidly in the open air. 

As soda exists in most soils, and is found in some form in 
most if not all plants, it is probably a necessary ingredient in 
soils; many of its salts, particuarly the nitrate, sulphate, chlo- 
ride and phosphate, are valuable fertilizers. 

POTASSIUM. 

This is the metallic basis of potash : it is bluish white when 
not exposed to the air, but by the contact of air it instantly 
oxidizes and becomes covered by a crust of the alkali, potash : 
when thrown in water, it takes fire and burns with a violet 
flame. At common temperatures it is soft and may be 
molded into any form, like wax: "at 32° it is quite brittle, 
and crystalizes in cubes; at 70° it is pasty, and at 150°, per- 
fectly liquid. At a dull red heat, it boils, forming a green 
vapor, and may be distilled." 



164 SCIENTIFIC AGRICULTURE. 

Like sodium, it is lighter than water; its specific gravity 
being 0.685. Potassium has a remarkable affinity for oxygen, 
which it abstracts from almost all other bodies. Its equiva- 
lent number is 39.3. Potash is a strong fixed alkah: it neu- 
trahzes the strongest acids, and its salts are numerous and 
important. Potassium is not found in an uncombined and 
pure state in nature, but in the form of an oxide : it exists in 
many minerals, nearly all plants, and in animal bodies. It is 
most abundant in the green and tender parts of plants, — the 
timber of forest trees contains comparatively httle. 

Its powerful action on other metals and earths, its caustic 
action on vegetable substances, and its almost universal pre- 
sence in soils and vegetation, show it to be an indispensible 
element of good soils, and a powerful fertilizer. Potash is 
rendered more caustic by mixture with quick Hme, — in this 
way it is beneficial in compost by facihtating the decomposition 
of vegetable matters. 

MAGNESIUM. 

Magnesium is found in the minerals, serpentine, talc, steatite, 
asbestos, augite, chrysohte and hornblende : it is always found 
combined with acids, or other earths, — it is found also in marl, 
and in small quantities in animal substances. It is a white, 
silver-like metal when pure, malleable, and fusible at a red 
heat, not changed by dry air, but slowly oxidized by damp air: 
it dissolves in dilute acids, giving off hydrogen gas, and form- 
inp* a salt of mao^nesia. 

Its equivalent number is 12.7. When heated to redness in 
the air, or in oxygen, it burns with briUiancy, and forms mag- 
nesia, or oxide of magnesium: it inflames spontaneously in 
chlorine. It exists in considerable quantity in nature, particu- 
larly in magnesian limestone. 

Magnesia slowly but entirely neutrahzes acids : it is inodorous, 
white, has a shghtly alkaline taste, absorbs and retains water 



SCIENTIFIC AGRICULTURE. 165 

to nearly tlie same degree as Kme, but is less caustic and 
alkaline. There are several important salts of magnesia, some 
of which are valuable as fertilizers, and indispensible to the 
growth of vegetation. 

CALCIUM. 

Calcium is a white silvery metal, heavier than water, — 
having a strong affinity for oxygen, with which it combines 
only in one proportion, forming lime. The equiv^alent number 
of calcium is 20.5. 

Lime is the most important and abundant of all the earths, 
being extensively distributed through the mineral kingdom, 
and constituting the principal earthy ingredient in the shells 
and bones of animals, and also existing in all plants. It is 
found in nature combined with carbonic acid, as in marble, 
limestone and chalk, in quantities so large as to form entire 
mountains. It is found combined with sulphuric acid, consti- 
tuting gypsum or plaster of paris: it is also combined with 
phosphoric, fluoric and arsenic acids. 

The minerals, calcareous spar, gypseous spar, arragonjte, and 
many others, are composed of hme. All natural waters con- 
tain more or less of this earth. Lime is a pure, white, alkaline 
earth : when burned lime is exposed to the air, it rapidly 
absorbs water, and falls into a fine powder, which is called 
"slaked hme," or hydrate of hme. This earth has a strong 
affinity for acids, with which it forms several salts. It is only 
sparingly soluble in water, and less so in hot than in cold 
water: when completely dissolved in clear water, it is called 
Hme water: this, when exposed to the air, unites with the 
carbonic acid of the air, and a thin pelUcle or layer of carbon- 
ate of hme is formed on the surface, — this soon falls to the 
bottom, and another layer is formed ; and so the process con- 
tinues until the lime all becomes a carbonate, and is thus 
precipitated from the water. 



166 SCIENTIFIC AGRICULTURE. 

Lime attacks and destroys both animal tissues and vegetable 
substances with rapidity, and mthout the exhalation of those 
noxious gasses and oftensive odors, which result when putre- 
faction goes on without the presence of Hme. Lime is valuable 
as a manure in soils destitute of this earth, by supplying an 
indispensible element to plants, and also by neutralizing 
acidity, dissolving silica, and decomposing insoluble organic 
matters, such as woody jfibre, humus, peat, ulmine, &c. The 
salts of lime are also of great value as fertilizers. 

MARL. 

Marl is a compound of lime and clay, so intimately mixed 
that their respective particles cannot be distinguished. The 
exact process by which nature combines the two elements is 
not known ; for if clay and lime be mixed together artificially, 
they form a substance quite different from natural marl : and 
according to Thaer, " it does not possess the faculty of losing 
its aggregation when exposed to the influence of the atmos- 
phere, and crumbhng to dust like natural marl." 

The proportions of the two elements are various : sometimes 
the lime predominates, sometimes the clay, and in some speci- 
mens they are equal. When the clay predominates greatly, it 
is called clay marl : when the lime predominates, it is called 
lime marl. Marl is found in considerable variety, both of com- 
position and color : it assumes a blue, red, yellowish or whitish 
hue, according to the oxides of iron, or other matters which it 
may contain : it is found in greater or less quantities in almost 
all countries, — sometimes on or near the surface, and in other 
cases at considerable depths in the earth. 

" It is confined [says Dr. Hitchcock,] to the alluvial and 
tertiary strata, and differs from many varieties of hmestone, 
only in not being consohdated." It often contains salts of 
potash and soda, fragments of shells, bones, and some vegeta- 
ble matter; that which contains a large quantity of shells is 



SCIENTIFIC AGRICULTURE. 16*? 

called shell marl: several other species of marl are described, 
the most important and valuable of wliich is greenstone marl. 

Nearly all the varieties, except stone marl, are easily pene- 
trated and their particles separated by water : frost is also an 
active agent in pulverizing it, — it is therefore often laid on 
land at the beginning of winter. Marl may be detected by 
the acids, with which it efifervesces and forms salts. It is 
evident from the character and composition of marl, that it is 
a valuable fertiUzer, especially on lands deficient in clay and 
Hme. 

Analysis of a specimen of marl from the Rhine, by Krocken. 

Carbonate of Lime, 12.275 

Carb. Magnesia, 0.975 

Potash, 0.087 

Water, 2.036 

Clay, sand and oxide of iron, - - - - 84.525 
Ammonia, 00.047 

GYPSUM. 

Gypsum is a compound of sulphuric acid, hme and water : 
it is sometimes found in the form of a soft yellowish white rock, 
with a texture resembhng that of loaf-sugar ; " but sometimes 
[says Lyell,] it is entirely composed of lenticular crystals." It 
is insoluble in acids, and does not effervesce, for the reason 
that it is already combined with sulphuric acid, for which it 
has a stronger affinity than for any other. A variety called 
anhydrous gypsum sometimes occurs, which contains no water. 

Gypsum is nearly insoluble in pure Avater ; — when deprived 
of its water by heat, it is called calcined gypsum, or " plaster 
of paris," — in this state if mixed with water, it may be formed 
into molds or casts, and it soon solidifies into a hard, white, 
compact mass. When calcined gypsum is long exposed to the 
air, it absorbs moisture, and is no longer fit for casts and stucco 
work, until calcined afresh. Gypsum can only be fused by a 



168 SCIENTIFIC AGRICULTURE. 

liigli degree of heat, — it does not then part with its sulphuric 
acid, but only loses its water. The origin of this rock is diffi- 
cult to explain ; it is found mostly among the new red sand- 
stone, but occurs also amono- other rocks. 

It is found in most countries in great abundance, and in 
various forms, as gypseous spar, gypseous stalactites and sta- 
lagmites, compact gypsum, &c., and in combination with clay 
and lime. Gypsum cannot be formed artificially. Water con- 
taining gypsum is called hard water. The decomposition cf 
gypsum can be easily effected by the alkaline carbonates: if 
powdered gypsum be boiled in a solution of carbonate of 
potash, a double decomposition, and also reunion, takes place; 
the sulphuric acid of the gypsum unites with the potash, anrl 
forms sulphate of potash, while the carbonic acid unites with 
the lime of the gypsum and forms carbonate of lime. Gypsum 
is one of the most valuable fertilizers known. 

CLAY. 

Clay is a compound of the two earths, silica and alumina, in 
a state of chemical union : it usuall}^ contains, also, an excess of 
uncombined silica in the form of sand. Proper q\^j is formed 
by nature alone, for no chemical process is known by which 
sihca and alumina can be made to unite so as to form real clay. 
It is usually colored by some of the oxides of iron, so as to 
present a bluish, yellow, red or brown hue. 

The two elements of clay are rarely contained in equal 
quantity; the silica almost always predominates, — sometimes 
to the amount of 93 per cent. Clay sometimes contains, an 
insoluble carbonate or phosphate of iron, w^hich are both 
thought to be injurious to vegetation. It sometimes contains 
also manganese and sulphate of iron, the last of w^hich, unless 
in a limy soil, is injurious to plants : organic matters are often 
found in clay, giving it a blackish hue and astringent properties. 




SCIENTIFIC AGRICULTURE. 169 

Clay lias been formed by the decomposition of rocks, such as 
granite, feldspar, clay slate, and argillaceous schist. 

Clay which contains neither iron nor vegetable matter, does 
not change color by heat : if it contains vegetable matter, it 
becomes lighter colored by heat; if colored dark by oxide of 
iron, it may become lighter by burning, on account of the iron 
changing its proportion of oxygen. White clay, which does 
not change color by heat, is nearly or quite pure. AVhen clay 
is dry, it absorbs water rapidly, becomes tenacious and adhe- 
sive, so as to retain any form or impression given to it; when sat- 
urated with water, it no longer allows that fluid to pass through 
it : it is from this cause that water stands long on the surface 
of the ground in swamps having a clay subsoil, — and tliis is why 
we find springs and water veins before we come to solid rock. 

When wet clay is exposed to frost, it is cracked or fissured, 
and sometimes completely pulverized, by the expansion of the 
water it contains, during freezing. It retains water with more 
tenacity than any other earth, and after being deprived of its 
water by heat, becomes hard. After being heated to redness, 
clay loses its ductile properties, is insoluble in water, and is of 
no use in the soil, until, by long action of the atmosphere, 
moisture, and animal manure, it is changed to its former con- 
dition. Clay does not effervesce with acids, unless it contains 
lime or carbonate of iron : it requires a high degree of heat for its 
fusion. Clay is often found in combination with gypsum. There 
are several varieties of clay, of which we notice only a few. 

Kaolin, or porcehiin clay, is the purest and finest, and is 

used in the manufacture of porcelain ware : it is of a yellowish 

or grayish white hue, and is supposed to be formed by the 

decomposition of feldspar. 

Pipe clay ranks next to kaolin in fineness, and is of various hues. 

Bole is a species of red clay, used in the manufacture of 
brown earthen ware. 

Potter's clay is used for bricks and stone ware. 



170 SCIENTIFIC AGRICULTURE. 

Clay iron ore contains carbonate and phosphate of iron, and 
has been described under the head of iron. 

PEAT. 

"Peat usually consists of soluble and insoluble geine, with 
a mixture of undecomposed vegetable matter and some earths." 
It is usually limited to the colder parts of the globe : it results 
mostly from the accumulation and decomposition of mosses, 
but also from any other vegetable matters which become 
mixed with it. 

The lower stratum of peat beds decays, while the plants on 
the surface continue to grow, thus adding new matter annually 
until they attain the thickness, in some cases, of thirty or forty 
feet. In tropical chmates, the heat produces decomposition so 
speedily that vegetables are resolved into their elements before 
peat can be formed. 

Peat is usually found also in low boggy or marshy districts. 
According to Dr. McCuUoch, " by the long continued action of 
water and other agents, the geine of peat is changed into bitu- 
men and carbon, which constitute lignite and bituminous coal : 
in a few instances the process of bitumenization has been found 
considerably advanced in beds of peat." 

Peat is remarkable for its power of presemng animal mat- 
ters from putrefaction. 

The following is an analysis of a specimen of peat from 
Massachusetts. 

Soluble geine .... 26.00 

Insoluble do. 59.60 

Sulphate of Lime, - - - 4.48 

Phosphate of Lime, - - - 0.V2 
Silicates, 9.20 



t 



100.00 
Peat yields also, according to a writer in the London Jour- 



SCIENTIFIC AGRICULTURE. iVl 

nal, ammonia, naptlia, oil, soda, and spermaceti: this is said ta 
be the discovery of a French chemist. 

That analysis generally shows the presence of these sub- 
stances is very doubtful. 

When the decay is far advanced, the peat is a dark colored 
and sometimes sohd mass : when less advanced in decomposi- 
tion, it is light brown, spongy, and contains pieces of vegeta- 
bles not yet disorganized, — in this state it is used in some 
countries as fuel Peat is sometimes sour, from the presence 
of phosphoric and acetic acids : it sometimes also contains am- 
monia; it decomposes slowly in the open air. \Yhen mixed 
with lime or potash and fermenting barn-j^ard manure, it 
becomes a valuable fertilizing agent, and may be used on any 
soil which requires the addition of vegetable matter. 

HUMUS. 

Humus is a brown or blackish colored substance, composed 
of vegetable matter in a state of decay. " Plumus [says Bous- 
singault,] is the last stage in the putrefaction of vegetable 
organic matter: its elements have acquired a stability w^hich 
enables them to resist all fermentation." "Humus is not pro- 
duced by the decay of pure woody fibre, but by that of wood 
which contains foreign soluble and insoluble organic substances, 
besides its essential constituents." — [Liebig.] It is of a spongy 
texture, easily pulverized, and nearly insoluble in water: it 
absorbs w^ater with such avidity as to contain three-fourths of 
its own weight without being moist. 

Weak acids have httle effect on humus, except to dissolve 
the alkaline and metalic or earthy matters which are usually 
mixed with it Potash and soda dissolve humus entirely, with 
the evolution of ammonia: from this solution, acids cause a 
precipitate of a brown inflammable powder resembhng ulmine. 
Humus contains more carbon and nitrogen than the vegetables 
from which it is derived : the nitrogen may be partly formed 
from the excrements of insects which five in the humus. 



172 



SCIENTIFIC AGRICULTURE. 



Mould is humus in a complete state of decomposition, or 
decay. 

May not humus and vegetable mould be increased in quantity 
by the growth among it of microscopic cryptogamous plants ? 

Humus contains, besides some mineral . elements, carbon, 
oxygen, hydrogen and nitrogen, phosphoric, sulphuric and 
humic acids. Humus is dissipated when exposed to the air by 
a slow combustion, with the disenp-aoement of carbonic acid. 
This, and all vegetable earths, are entirely destructible. Salts 
are formed during the decomposition of humus, by the union 
of bases with the humic acid, — these are called humates. 

Besides the above elements, humus contains, according to 
Berzelius, humic, crenic and apocrenic acids, and traces of 
glairin. Humus is an indispensible ingredient in all fertile 
soils, hence the necessity of replacing it in the soil as fost as it 
is exhausted. 

Agriculturists who think to supply the place of manure by 
frequent and deep ploughing, have been disappointed, and 
their fields have been gradually impoverished by crops, imtil 
they became barren. When humus is put on a clay soil, it is 
retained with such tenacity by the cla}^, that the free contact 
of air is prevented, and it decomposes more slowly, — for this 
reason clay requires a larger quantity, other things being 
equal, to produce the same effects, than other soils. 

Sand allows free access of air to the humus, which is incor- 
porated wdth it, and thereby favors its decomposition and 
consequent fertilizing power. Unchanged humus affords no 
nutriment to plants; it udergoes chemical change to be fitted 
for this purpose. Lime and potash destroy the acidity of 
sour humus, and favor its decomposition: sour humus con- 
tains an insoluble extractive matter, w^hich is injurious to vege- 
tation. A soil which abounds in sour humus produces little 
but reeds, rushes, flags, sedge, and other poor and unpalata- 
ble plants: such soils are rendered fertile by draining, burning 
and alkalies. 



CHAPTER HI. 



• PHYSICAL PROPERTIES OF SOILS. 

The physical properties of soils necessary to be considered 
are, density, weight, state of division, firmness and adhesive- 
ness, power of imbibing moisture, power of containing water, 
power of retaining water, capillary power, contractibility on 
drying, power of absorbing gaseous matters, power of absorb- 
ing heat, power of containing heat, and power of radiating 
heat. 

The weight of a soil depends upon its density, or the 
proximity and density of its particles. Dense soils retain heat 
longer than light ones, and afford a firmer support to the roots 
of plants. 

The following table from Johnston, shows the relative 
weight of several soils. 

A cubic foot of dry silicious or calcareous sand weighs 180 lbs, 
" half sand and half clay « 95 

" " of common arable land " 80 to 90 

" " of pure agricultural clay " 75 

" " of rich garden mold " VO 

" « of a peaty soil "39 to 50 

The state of division of the particles composing the soil has 
an effect upon its weight, as well as money value. A soil 
composed of clay, sand, coarse and fine gravel and vegetable 



174 SCIENTIFIC AGRICULTURE. 

mold, is superior in all respects to one composed of either of 
these ingredients alone. 

Firmness and Adhesiveness. — Most soils become hard and 
stiff in some degree, by the cohesion of their particles after 
being thoroughl}^ wet. Clay soils become hard and difficult to 
pulverize when thoroughly dried, while pure sand soils scarcely 
cohere at all. This varies accordino- to the relative amount of ■ 
sand and qI-aj or lime in the soil. The practical inference is^B 
that a sandy soil is improved by clay, and a stiff clay soil is ( 
ameliorated by sand. \ 

The 2^ower of imhihlng moisture is possessed by all fertile 
soils. In dry weather, this quality in soils is highly important, 
in order that moisture may be absorbed from the dews of the 
night, to compensate to the roots of plants what they had lost 
by exhalations from their leaves and evaporation from the soil, 
during the day. 

During a night of twelve hours, when the air is moist, * 
according to Schubler. 

1000 pounds of perfectly dry quartz sand will gain lbs. 
" " Calcareous '' " 2 

" Loamy soil " "21 

" " Pure agricultural clay " "27 

" " Rich peat}^ soils, still more. 

Poiver of containing wafer, in dr}'- climates, constitutes one 
of the most important characteristics of arable soils. A good 
soil for ploughing or tilling must be capable of containing from 
80 to 70 per cent, of its weight of water: soils which allow 
their moisture to sink down immediately after rains, below the 
reach of the roots of plants, are valuable only " for pine plan- 
tations or laying dovv^n to grass. — [Johnston. 

The following table from Schubler shows the relative capacity 
of soils for containino' water. Bv this, Ave mean, the amount 
of water which a given quantity of earth will imbibe and 



SCIENTIFIC AGRICULTURE. 175 

contain, before it is saturated or full, so as to allow the water 
to drop or run out. 

From 106 lbs. of dry soil, the water will begin to drop, if it 

be a quartz sand, when it has absorbed 25 lbs. 

Calcareous sand, " " " " 29 

Loamy soil, " " " " 40 

English chalk, " " « « 45 

Clay loam, " " " " 50 

Pure clay, " " " " 70 

Power of retaining water. — Evaporation is constantly going 
on from the surface of the earth, except when the atmosphere 
is saturated, or rain or dew is falling. The rapidity with which 
soils become dry after rains, depends upon the tenacity with 
v/hich they rettiin water : as a general rule, those soils which 
are capable of containing the most water, also retain it with 
the greatest tenacity. Thus a sand soil will lose as much 
water in one hour as a cla}^ in three, or peat soil in four hours. 
On this property depends in a great degree the warmth or 
coldness of a soil. 

The capillary poioer of the soil is exhibited by pouring 
water into the bottom of a flower pot, when it will be seen 
that the earth graduall}^ takes up the water, and the moisture 
soon appears on the surface. In the same way the surface 
soil absorbs moisture from the subsoil ; and when this contains 
an excess of water, the surface is also too wet and cold. Open, 
porous soils, such as sand, peat and humus, possess greater 
capillary power than stiff clay. Upon this action the soil is 
dependent for its supply of moisture during dry weather: 
upon this, also, the roots of plants are dependent for a supply 
of soluble saline matters, wliich, during ]-ains, have been 
Avashed down into the subsoil beyond their reach. This is the 
principal means by which, in hot, dry climates, Avhere rains 
seldom or never fell, the soil obtains sufficient moisture to 
produce vegetation. This capillary action explains the exis- 



176 SCIENTIFIC AGRICULTURE. 

tence of the tliick crusts of nitrate, carbonate and chloride of 
soda, which are met with in Peru and other parts of South 
America, India and Egypt. These salts are brought to the 
surface by capillary action, in a state of solution, and deposited 
as the water evaporates. 

Contractibility on drying. — Some soils contract or shrink 
on becoming dried after rain, much more than others; and 
this appears to be in proportion to their power of retaining 
water. Thus clay and peat diminish in bulk one fifth on being 
perfectly dried after saturation, while sand maintains the same 
bulk in either state. — [Johnston.] This contraction in clay 
soils has a tendency to tear and injure the small and tender 
roots of plants. 

Power of absorbing gaseous matters. — The necessity of free 
access of air to the soil has already been noticed; and in 
proportion to the amount of air which is admitted into the soil, 
will be the oxygen and other gases absorbed and made avail- 
able to the roots of vegetation. Clays, peat and humus absorb 
more oxygen than sandy soils; this is due partly to difference 
in porosity, and partly to the chemical character of each. Be- 
sides oxygen, soils absorb carbonic acid, ammonia, nitric acid, 
and other vapors which contribute to fertility. All soils absorb 
gaseous substances the most readily when in a moist state; so 
that dews and showers are of great benefit, in bringing the soil 
into a condition to extract from the air fresh supplies of the 
gases. 

Power of absorbing heat. — The earth is capable of absorbing 
heat during sunshine, so as to attain a temperature above the 
surrounding air. Dark colored, brown and reddish soils absorb 
heat most rapidly, and become warm the soonest. They also 
become from three to eioht deo-rees warmer than other colored 
soils, and by this means they promote the growth of vegetation 
better than those of other colors. This property gives an 
additional value to dark soils over hght ones, in countries 



SCIENTIFIC AGRICULTURE. 177 

where sunsliine is deficient, and in fields Avhich have a northern 
aspect. 

Power of retaining heat — As heat always tends to seek an 
equilibrium, it follows that after the sun has disappeared, and 
his rays cease to shine on a particular part of the earth, the 
amount of heat which it has absorbed above that of the air is 
gradually given off again to the latter, until their temperature 
is equal, or until the air becomes the coldest, — as in frosty 
nights. A peat soil cools more quickly than clay, and clay 
more quickly than sand. This difference must have an influ- 
ence on the growth of crops. In cold, wet soils, the property 
of radiating heat slowl}^ compensates in some degree for the 
injury done to plants by these conditions. It also prevents the 
formation of dew and frost, as soon as would otherwise be the 
case. On the contrary, soils which radiate heat faster, promote 
the formation of dew by becoming cooled below the dew point 
sooner, and in this way compensate in some small degree for 
deficiency of rain. 

The absorbing, as well as radiating power of the soil, may 
be increased by a top dressing of soot, charcoal, muck, or some 
dark colored manure. The principle of absorption and radia- 
tion as dependent upon color, holds true in relation to p>lants^ 
as loell as to soils : and, if all other conditions are favorable, 
the light colored, (ivhite straiv,) crops should be cidtivated on 
dark colored soils, and the dark colored, [green straw,) crops 
on the light colored soils.'^ 

The study of the mechanical and pliysical properties of 
soils is of more importance than has generally been supposed. 
These have now been discussed as fully as limits w^ould admit, 
and we conclude the subject by stating finally, what are the 
ultimate uses and relations of the soil to plants. 

* This idea is original with the author, so far as he luiows: whether 
of any value or not, others may judge and decide. 



l78 SCIENTIFIC AGRICULTURE. 

First, the soil serves as the foundation for upholding and 
gi\dng mechanical support to the vegetable structure. 

Secondly, it absorbs light, heat, air and moisture, which are 
indispensible to healthy vegetation. 

Thirdly, it supplies both the oi'ganic and inorganic elements 
required by the plant as food. 

Fourthly, it is a chemical laboratory, in which these ele- 
ments are constantly being prepared to be taken into the plant 
by its roots. 



CHAPTER IV. 



TILLAGE. 



All operations upon the soil for its improvement and pre- 
paration for crops, may be included under the two heads of 
tillage and stercology^ or manuring. Tillage includes the 
operations of draining, irrigation, paring and burning, rotation 
of crops, fallow, extirpation of weeds and insects, ploughing, 
ribbing, lapping, laying in beds, scarifying or grubbing, subsoil 
ploughing, trenching, rolling, harrowing, hoeing, spading, &c. 

The objects of tillage are, — 1. To loosen the soil and render 
it permeable to air, \yater and the roots of plants. 2. To bring 
up the subsoil and mix it with the surface. 3. To incorpo- 
rate manures with the soil. 4. To allow free access of the 
heat and hght of the sun. 5. To pidverize the coarse and 
compact portions. 6. To destroy weeds and insects. T. To 
bury green crops designed for manures. 8. To render wet 
soils dry and arable. 9. To supply a sufficiency of water to 
dry soils. 10. To fix moveable and hght blowing soils. 11. To 
clear the soil of roots and stones. 12. To cover seeds with 
soil after solving. 

The following operations are described by Colman, and are, 
part of them, pecuhar to the agriculture of Europe. 

Lapping consists in turning a furrow upon an unploughed 
surface, so that when the field is finished, it is only half 
ploughed. 



180 SCIENTIFIC AGRICULTURE. 

RihUng resembles lapping, except that two furrows, instead 
of one, are turned upon the same unploughed space. 

Stitching or laying in beds consists in turning two furrows, 
back to back, and then plougliing alternately on either side, 
until the bed is from 5 to 60 feet wide, and leaving deep fur- 
rows between all the beds. 

Trench ploughing consists in making a deep furrow, by- 
ploughing one furrow directly in another. 

Subsoil ploughing consists in breaking up and loosening the 
subsoil Avith a plow for that purpose, and without inverting the 
surface. 

Scarifying or gruhhing differs from harroAving only by being 
performed with a cultivator or similar instrument, which goes 
deeper into the earth than the common harrow, for the purpose 
of pulverizing the soil, and bringing up roots and stones to the 
surface. 

The other operations of tillage need not be described, as 
they are common and well understood. There can be no 
question that much of the success of productive agriculture 
depends upon the perfection of tillage. A perfect tillage 
requires the combination of patient labor, mechanical imple- 
ments of the best construction, and skill in the operations. 

A poor soil well tilled may produce better crops than a good 
soil without tillage. Thorough tillage, by mixing and pulver- 
izing the soil sufficiently, is a means of saving manures and 
greatly increasing the return of the harvest: it is not, however, 
true, as once supposed, that tillage will supercede the neces- 
sity of all manures ; it only compensates for part of the manure 
requisite, and facihtates the operation of that which is applied. 
The Chinese, and some nations of Europe, have, by a perfect 
system of tillage, rendered barren soils fertile, and caused 
fertile soils to yield harvests of almost incredible amount. 



SCIENTIFIC AGRICULTUJRE. 181 



IRRIGATION. 

Irrigation lias been practiced by the Chinese and Egyptians 
from the remotest antiquity. In countries where rains seldom 
fall, and the ground becomes dry and parched, irrigation is of 
immense value. It consists in taking -water from lakes, se\Yers, 
runnino- streams or reservoirs, and causino- it to flow over the 
land by means of small canals or furrows, then by proper out- 
lets to carry it off again. It is confined, according to Colman 
and Johnston, almost exclusively to meadow lands. 

The benefits of irrigation in a country where rain falls fre- 
quently and abundantly, are the same as those of manuring. 
When the water used holds in suspension any organic matters, 
they subside while the water remains on the fields, and leave 
a visible layer of manure on the surfece, after the water is 
drained off. An example of the fertilizing effects of irrigation 
is seen in the lands alono- the banks of the Nile and Gano-es. 
But the eftects of irrioation with water that contains no oro-anic 
sediments, must be considered the same as that of rains. Run- 
ning water furnishes to plants some gases, which are absorbed, 
and in this way are beneficial. Crops of young and tender 
plants should be irrigated by pure water: it may be repeated 
every two or three Avecks when there is an}'- want of rain, and 
the water be allowed to lie on the field only three or four daj-s. 
It is thought by English agriculturists to be injurious to mea- 
dows to flood them immediately after mowing. 

Warjnng is a process similar to iriigation: the object of 
this, however, is more especially to obtain the sediments of 
muddy streams, &c. ; the water should never be allowed ni 
either process to remain on the field until stagnated. Irriga- 
tion is most beneficial on land which is well drained beneath, 
so as to allow the water to penetrate the subsoil, and not stand 
too lono- on the surface. Meadow lands are sometimes water- 
ed in the Annter to prevent the injurious eflects of frost upon 



182 SCIENTIFIC AGRICULTURE. 

the roots of tlie grass. Irrigation is not practiced to much ex- 
tent in the United States ; and the remoteness of many farms 
from streams, as well as the expense attending the operation, 
will prevent its universal application, even where it would be 
beneficial. 

PARING AND BURNING. 

Paring and burning is much practiced in many parts of 
Europe, particularly in Great Britain ; but, so far as we are 
informed, it is but little practiced in the United States. It is 
done mostly upon sward, peat and . turf soils. The operation 
consists in removing, with a plow or spade, a slice from the 
surface, from one to three inches thick: this is piled up in 
small heaps along with other combustible matters, such as 
brush, weeds and decayed wood ; these, when sufficiently dry, 
are fired and allowed to smoulder and burn slowly until the 
whole is reduced to ashes. The ashes are then spread evenly 
over the surface of the soil. The quantity of ashes which is 
sometimes obtained in this way at a single burning, is stated 
by Colman to be 2,660 bushels, or about 77 tons per acre. 

The benefits of paring and burning are, — 1. It disintegrates 
and reduces to fineness, some stones and hard clay. 2. It de- 
stroys insects, with their eggs and larvae. 3. It reduces vege- 
table matter to ashes and gases, which are available for the 
immediate food of a crop of plants. There are some objec- 
tions to this process, which ought to be stated, as it involves 
some principles not wholly understood. 

One objection is that it consumes too much of the vegeta- 
ble and organic matters of the soil : another is the amount of 
labor required in the operation. The benefit however, of par- 
ing and burning upon cold, moist, sour, peat and turf soils, is 
unquestionable. The lime and potash produced, serve to 
neutralize acids in the soil, and the iron, if it contain any, is 
brought to a higher degree of ox3^dation. 

On light, sandy, gravelly soils, where vegetation is thin and 



SCIENTIFIC AGRICULTURE. 183 

there is little organic matter present, tliis practice is injurious. 
The process of burning, according to Boussingault, ought to 
cease after the organic matters are reduced to a blackish ash ; 
for when carried beyond this, so that incineration is complete 
and a red ash is left, it may materially injure, if not render 
the soil barren. 

DRAINING. 

The draining of wet lands has become one of the most im- 
portant branches of mechanical agTiculture. An excess of 
water in the soil prevents the access of air, reduces the tem- 
perature, favors the formation of frost, fogs and mildew, and 
renders tillage difficult or impossible. Soils may be rendered 
too wet in various ways, as, by the tides of the sea, by the 
setting back of rivers, by permanent springs in the soil, by 
small subterranean streams, and by the compact and retentive 
nature of the soil or subsoil. The advantages of draining, and 
the various modes by which it is best accomplished, are well 
described by Johnston and Colman, from whose works the fol- 
lowing facts in relation to the operation are derived. 

1. It carries off all stagnant water, and gives a ready escape 
to the excess of what falls in rain. 2. It prevents the ascent 
of water from below, either by capillary attraction, or springs. 
3. It allows the water of rains to penetrate, and find a ready 
passage from the soil, instead of wasliing the surface. 4. The 
descent of Avater through the soil is followed by fresh air, which 
occupies the space just left by the water. 5. The soil after 
thorough draining becomes looser, more friable and easily 
broken; this is especially true of stubborn clays, wliich in 
practice become altogether another soil. 6. By freeino- the 
soil from the excess of water, it becomes warmer, and thereby 
advances the crop to an earlier harvest : thus it is " equivalent 
to a change of climate.'' 7. When the autumn is wet, drain- 
ing carries off the superabundance of water, and prepares the 
land for sowing fall crops, wliich would otherwise be retarded, 



184 SCIENTIFIC AGRICULTURE. 

or altogether prevented. 8. In its consequences it is equiva- 
lent to an actual deepening of the soil. 9. In wet soils, bones, 
wood-ashes, rape- dust, nitrate of soda, and other artificial ma- 
nures are almost thrown away. 10. He who drains confers a 
benefit upon his neighbors also. 11. It produces a more salu- 
brious climate, and conduces greatly to the health and moral 
happiness of the whole population. 

Several different modes of draining are practiced in Great 
Britain, which are worthy of notice — some of them are also 
known and practiced in the United States. The process of 
draining by open 'ditches is the rudest, and was doubtless the 
first form of draining. Covered drains were next substituted, 
of various construction. One form of these is made by dig- 
ging a ditch, and then filling it with straw or faggots, and cov- 
erino- it over "with the earth which was thrown out. Another 
form is excavated so as to taper to a point at the bottom, and 
having a shoulder left at the height from the bottom which it 
is desirable to cover the v<^ater-course. This is then covered 
by an inverted sod, which rests on the shoulders ; after which 
the earth thrown out in excavating is returned, and the surface 
levelled. Another process is by the mole plow : another by 
fillino- the bottom of a ditch with small stones of uniform size. 
Two other forms, called in England tile and ^;?pe drains, are 
constructed by means of tile and pipes made of brick clay, 
and are said to form water-courses which are both cheap and 
durable. 

FALLOWING. 

" By fallowing, it has been known in all ages that the produce 
of the land Avas capable of being increased. How is this in- 
crease to be accounted for ? We speak of leaving the land to 
rest, but it can really never become wearied of bearing crops. 
It cannot, through fatigue, lie in need of repose. In what, then, 
does the efficacy of naked fallowing consist ?" — [Johnston. 

Some agricultmists reject the practice of fallowing as use- 



SCIENTIFIC AGRICULTURE. 185 

less, upon the supposition that all the objects accomplished by- 
it, may be also by the application of manures. The proposal 
to substitute manures, is of course equivalent to an admission 
that fallow is beneficial to the soil. Now if any change takes 
place in the soil while lying in fallow, we must first know what 
that change is before we can determine whether manures will 
affect the same change : and in order to know this, we must 
have an exact analysis of the soil, before the fallowing begins, 
and at the end of its term ; this will show what new elements 
are formed, and what old ones are decomposed. 

If, then, we have a manure which will furnish to the soil all 
the elements which were formed by chemical action during fal- 
lowing, it will fulfil the same indication. But in either case, 
an analysis of the soil is requisite before the fact can be estab- 
lished: and inasmuch as those who discard fallowino- have 
made no such analysis, they have made no demonstration of 
the truth of their position. And until further facts are de- 
veloped by chemical experiment, it may be fairly questioned, 
whether, on all soils, and under all circumstances, fallow can be 
dispensed with. The benefits to be derived from allowing land 
to lie in naked fallow are enumerated by Johnston as follows : 

1. In strong clay soils, fallow affords opportunity for destroy- 
ing weeds, which it is difficult to extirpate while the land is 
continually bearing crops. 2. The weeds and herbage which 
spring up during summer, afford an abundant crop for green 
manure: they should be ploughed under before their seeds 
ripen. 3. Land which is continually cropped, becomes ex- 
hausted of certain elements within the depth to which their 
roots extend. By leaving the soil at rest, the rains which fall 
and circulate through it, equalize the distribution of the solu- 
ble substances which it contains. The water which in dry 
weather, ascends by capillary attraction from below, brings up 
saline compounds and deposits them as it evaporates. 4. Some 
subsoils require to be turned up and exposed to the action of 



186 SCIENTIFIC AGRICULTURE. 

the air for some time, before tliey can be safely mixed with 
the surface soil. 5. The soil often contains more or less 
organic matter which is inert, or decays so slowly as to be 
almost unavailable to vegetation : by leaving this to decompose 
and become fitted for the food of plants, the crop which fol- 
lows will grow more luxuriantly and yield more abundantly. 
6. The niti'ates, which are veiy favorable to vegetable gTOwth, 
are more rapidly formed when the land lies in naked fallow 
than when covered with crops. 7. The fragments of rocks of 
various kinds are disintegrated and decomposed faster during 
fallow than during cropping. 8. The sahne and other sub- 
stances such as ammonia, magnesia, the nitrates, &c., which 
are brought down by rains, accumulate in the soil during fal- 
low. 9. The clay, oxide of iron, and organic matter of the 
soil, have the power of extracting ammonia from the air ; and 
this is the more I'apid, the greater the extent of surface which 
is uncovered and exposed to the passing air. 10. The light 
soils sometimes become too loose to afford sufficient mechani- 
cal support to the roots of crops, and require time to settle 
together and resume their cohesion and compactness. 

Disintegration of a solid body, takes place with a rapidity 
proportioned to its surface exposed, — so that by turning over 
fldlow by the plow, more surface is exposed to the air and 
other causes, in a given time, and a greater amount of silicates 
and other inorganic elements are dissolved : some fields require 
two or three years to dissolve sufficient sificates for a crop of 
siHca plants, — this process is hastened by lime and potash. 

No doubt the period usually allowed to land to fie in fallow 
may in many cases be yarj much abridged, and in some cases 
altogether dispensed with. Whenever fallow is beneficial, it 
must be ascribed to some one or more, if not all the above 
causes combined. 

ROTATION OF CROPS. 

By rotation of crops, is implied, the alternate production of 



SCIENTIFIC AGRICULTURE. 187 

different plants in regular succession on the same land. Expe- 
rience has shown that the same crop cannot be produced 
successively on the same field for an indefinite period of time. 

The grasses and forest trees seem to present an exception 
to this principle : but it must be observed that the grasses are 
mowed or pastured down before arriving at maturity, — for, if 
they were allowed to perfect their growth and ripen their 
seeds, the same result would follow as in other crops. And 
with regard to forest trees, it has been observed that where an 
oak forest has been cut down, a growth of pine will succeed ; 
and where a pine forest has been cleared away, a growth of 
oak will spring up in its place : where beech and maple are 
cut, poplar and basswood often succeed them. Thus it appears 
that the soft and hard woods alternate with each other. 

The reason formerly given for the necessity of rotation was, 
that all plants throw off certain matters or excrements by their 
roots, which prove injurious to another crop of the saine kind 
of 2ylc(iits; but lohich are beneficial rather than injurious to 
crops of a different hind. 

This beautiful theory originated with the distinguished bota- 
nist, DecandoUe, and explains, apparently, in an easy and satis- 
factory manner, all the reasons for the necessity of rotation 
of crops. The simplicity and high authority of this theory 
obtained for it, for many years, an unquestioned assent; and 
the only objection which lies against it now is, that it is not 
supported by a single fact. 

The objections to it are, — 1. That plants do not excrete so 
great an amount of noxious matter as supposed by Decan- 
doUe. 2. No evidence exists of their injurious effects upon 
the plants from which they are excreted. 3. There has been 
no demonstration of their nutritive effects on other plants. 

This theory, then, must be abandoned, and we must look 
for one which is supported by facts : and if one cause be found 
adequate to explain all the effects produced, we are not bound 
to seek for another. 



188 SCIENTIFIC AGRICULTURE. 

The necessity of rotation does not depend upon there being 
too much, but too little, of some particular elements in the 
soil. — [Johnston.] All plants require certain elements for food, 
and these are indispensible to their growth and maturity: one 
plant requires them in certain proportions and another requires 
these and others besides, in quite diflferent proportions. 

" If we assume, [says Petzholdt,] that the utility of the rota- 
tion of crops depends exclusively upon the circumstance that 
all cultivated plants withdraw from the soil unequal amounts 
of certain ingredients for their nutrition, all the observed facts 
are at once satisfactorily explained, and the possibility of deter- 
mining the rotation of crops, or of avoiding it altogether, if 
desirable, made evident." 

It is useless to remark, that no plant can vegetate in a soil 
which does not contain all the elements which it requires for 
its food. Some species of grass contain, and therefore require 
for their gTOwth, a large amount of silica : a soil which contains 
no silica cannot produce them. A soil may contain just enough 
silica for one crop, but not enough for a second, so that a second 
could not be produced ; but a crop of some other plant requiring 
much less sihca, might be grown upon it as successfully as the 
grass before. 

"A single crop of wheat may deprive the soil so completely 
of one of its mineral constituents, that another crop of wheat 
could not grow upon it ; and yet this soil may contain abundant 
mineral constituents for the production of a good crop of clover 
or turneps." An anatysis of a soil and the ashes of plants 
desired to be produced upon it wiU determine negativehj, 
whether it is eligible to their growth: but the only positive 
proof is a trial of the crop upon the soil. 

Two plants growing side by side share equally of the ele- 
ments of the soil: two of the same kind require the same 
elements, and are prejudicial to each other: two plants requi- 
ring different elements may grow side by side without being 
mutually injurious, but both flourish equally well. 



\ 



SCIENTIFIC AGRICULTURE. 189 

All plants draw certain mineral elements from the soil, but 
do not all equally exhaust its fertility. All knowledge respect- 
ing the appHcation of manures, and the adaptation of certain 
plants to particular soils, is based upon these facts. The 
necessity for rotation may sometimes be obviated by allowing 
the land to lie in fallow for a year, after which the crop 
may be successfully repeated. Manuring may also sometimes 
answer the same purpose ; but as a general rule in 'practice, 
however it may be explained in theory, a judicious rotation is 
beneficial. 

Boussingault states that he saw in South America, fields on 
which good crops of wheat were said to have been produced 
annually for more than two centuries ; and also that potatoes 
are cultivated continually on the same soil. It is stated also 
by Colman, that onions yield more and more abundantly the 
oftener they are grown on the same field. These statements 
either contain some hidden fallacy, or they prove that the fields 
in question contained an inexhaustible amount of the elements 
necessary to the plans produced ; for they do not, nor were 
they designed to prove, that rotation is unnecessary. 

It is unquestionable that a perfect system of agriculture, 
and the maximum production of all crops, requires a system 
of alternation, reo-ulated accordino- to circumstances, and in 
accordance with the principles of Chemistry. A valuable end 
to be obtained by rotation is the destruction of certain weeds 
and the insects which inhabit them. 

The following table shows a system of rotation which is 
practiced in Pennsylvania. 

First year — Grass or clover. 

Second " Pasture. 

Third " Indian corn. 

Fourth " Oats or barley — (manured.) 

Fifth " Wheat. 

Sixth " Grass — (plastered.) 



190 



SCIENTIFIC AGRICULTURE. 



The tables below are from Colman, and show some courses 
of rotation practiced in England. 
First year — Turneps — (manm-ed.) 
Second " Barley. 
Third " Clover. 
Fourth " Wheat. 

On a Clay Soil. 
First year — Swedes turnips and Mangel Wurtzel. 
Second " Wheat and beans, (i. e., part of land in each.) 
Third " Clover. 
Fourth " Wheat and oats. 
Fifth " Vetches, rye and turneps. 
Sixth " Wheat. 

On a Sandy Soil. 
First year — Swedes and Mangel Wurtzel. 
Second " Barley. 
Third " Clover. 
Fourth " Oats. 

Fifth " Cabbage and potatoes. 
Sixth " Wheat. 

On a Limestone Soil. 

First year — Rye and turneps. 

Second " Barley. 

Third « Clover. 

Fourth " Oats. 

Fifth " Turneps. 

Sixth " Wheat. 

The table below is from Mr. J. J. Thomas' Prize Essay : it 
gives three courses, which are said to be well adapted to the 
State of New York. 

J^irst Course. 

First year — Corn and roots, well manured. 

Second " Wheat sown with 15 lbs. clover seed per acre. 



SCIENTIFIC AGRICULTURE. 191 

First Course — continued. 
TMrd yeai' — Clover one or more years, according to fertility 
and amount of manure at hand. 
Second Course. 
First year — Corn and roots, with manure. 
Second " Barley and peas. 
Third " Wheat, sown with clover. 
Fourth " Clover, one or more years. 

Third Course. 

First year — Corn and roots, with manure. 

Second " Barley. 

Third " Wheat, sown with clover. 

Fourth " Pasture. 

Fifth " Meadow. 

Sixth " Fallow. 

Seventh " Wheat. 

Eio-hth " Oats sown with clover. 

Ninth " Pasture or meadow. 

It will be evident, on a little reflection, that no definite rules 
can be given, and no set of tables devised which shall apply to 
all soils and under all circumstances. The frequency of any 
crop in the course of rotation, must, therefore, be determined 
by a consideration of the character of the soil and subsoil, the 
amount of manure applied, and the other crops which come 
in the course. 

" In wheat farmino- districts and with the wheat farmer, 
who depends for his sales and profits solely upon wheat and 
wool, the following rotation, with slight variation, is often 
adopted : 

" Di\'ide all the available land into three, six, or nine enclo- 
sures: let one-tliird be always in wheat, one-third in pasture 
and meadow, and one-third in summer crops well manured, — 
which may be followed with wheat the same fall, or may be 



102 SCIENTIFIC AGRICULTURE. 

put in barley the next spring, and followed with wheat and 
well clovered in all cases. The general practice is, to summer- 
fallow the clover after spring pasturing. There should be 
about one sheep to the acre of all the available land: the 
manner of cropping the fallow is important. 

** Others make a four years' rotation, letting the clover lay 
two years, — one for pasture and one for meadow. On this 
system no more cattle should be kept, or butter and cheese 
made, or corn, oats or potatoes grown, than is required for the 
farai use ; every thing is made subser-^ient to the wheat crop." 



CHAPTER V. 



STERCOLOGY "^ MANURES. 

All a^'ents used by the Agriculturist to preserve or restore 
the productiveness of the soil, are properly called manures. 
All soils, after being long cultivated and subjected to the ex- 
hausting influence of continual harvests, become deficient in 
mineral and organic elements, which must be replaced artifi- 
cially or total barrenness will ensue. Manuring is the process 
by which tliis end is accomplished, — and for it there is no 
substitute. 

If the supply be less than the crops require, the soil increases 
in barrenness : if it just replaces what has been removed by 
the crops, the fertiHty remains the same ; if more be added 
than the crops require, the fertility of the land is increased. 

* " A New Term — Stercology. — Mr. Editor : I wish to propose, 
tliroug^h your paper, a new term, which I think will supply a deficiency 
in agricultural language. We have no generic term which embraces in 
its signification, the science or art of enriching the soil. I therefore 
propose the term Sthrcologt, which is compounded from the word 
stercus, which means manure, and logos, a discourse. 

"Although hardly general enough in its strict meaning, this word may, 
by a little extension, be understood to embrace everything under the 
head of manuring, enriching, ameliorating or amending the soil. And 
although words are only the signs of ideas, and technical language 
should not be used unnecessarily, — still a systematic division of any 
branch of science into parts embraced under generic heads is always 
convenient. 

" Yours, respectfully, 

"M. M RODGERS. 

" Genesee Farmer August, 1847." 

9 



194 SCIENTIFIC AGRICULTURE. 

The remains of plants, together with the excrements and car- 
casses of animals, if returned to the soil before decomposition, 
must contain all the mineral, organic and gaseous elements, 
which the plants derived from the soil or the atmosphere. 
These must pass through the different processes of decompo- 
sition, before they assume their original gaseous and earthy- 
forms, and become again available for the food of plants. 

The whole science of manurino- consists in supplying to the 
soil, those indispensible elements which have become exhaust- 
ed. The richest manure may be applied to a failing soil, and 
if it lacks a particular element which the crops require, and 
which the soil does not contain, the soil grows barren notwith- 
standing the manuring. Farm-yard manure, probabl]' contains 
the greatest number of elements necessary to fertility ; but par- 
ticular plants require special manures. 

Manures operate beneficially on the soil in several wayi^ 

1. By serving directly in some instances as the food of plants. 

2. By causing chemical changes in the soil, by which other 
substances are prepared to be taken up as nutriment by their 
roots. 3. By neutralizing noxious substances in the soil which 
prevent the growth of vegetation. The operation of lime on a 
cold, sour, peat soil, or one which abounds in sulphate of iron, 
is an example of this principle. 4. Manures change, accord- 
ing to their bulk and texture, the mechanical properties of 
soils. 5. They may chenge more or less, according to their 
various properties, the physico-chemical character of a soil, in 
relation to light, heat, air and water. Sand, used upon a claj 
soil, for the purpose of rendering it more loose and friable 
would be as properly a manure as farm, yard, or any other 
variety. Clay used to ameliorate a sandy soil, is also in efifect 
a manure. 

Manures have been classified in various ways, according t» 
their supposed operation and nature. The most simple and 
convenient division, and one which is usually adopted at pre- 



i 



SCIENTIFIC AGRICULTURE. 195 

sent, is that which arranges all of them into three classes, viz,: 
animal, vegetable and mineral manures. The first class includes 
all substances of animal origin : the second includes all those 
of vegetable origin: and the third, all those derived directly 
from the mineral kingdom. 

ANIMAL MANURES.* 

Animal substances are better fertilizers than those of vegeta- 
ble orioin, on account of their chemical constitution and the 
facility with which they decompose ; they furnish more manure 
in proportion to their bulk, and act more promptly and rapidly. 
The properties and value of these substances are given mostly 
on the authority of Johnston and Boussingault 

The Jlesh of animals, after and during its decomposition, is a 
rich and active manure: the lean Jlesh acts more energetically 
than the fat 

Blood is similar in its properties to lean flesh ; it is sometimes 
applied as a top dressing in the form of dried powder, and 
sometimes mixed with other matters, to form composts. The 
scraps of shin among the refuse of curriers' shops are also 
used as manure. 

Wool, hair, horns and hoofs found in large quantities among 
the refuse of various manufactories, contain large proportions 
of carbon and nitrogen, as do most animal substances, and are 
therefore highly concentrated manures. The refuse of fisheries, 
soap and candle factories, slaughter houses, kitchens, sugar 
manufactories, (fee, all contain matters rich in those elements 
which characterize good fertilizers. 

Ani77ial charcoal, which is to be obtained in considerable 
quantities at sugar refiners' shops, in a state of mixture with 
blood and lime, is a manure of considerable value. 

Bones are valuable on account of both the organic and 
mineral matters which they contain. The bones of diflferent 

• See tables at the end of the chapter. 



1&6 SCIENTIFIC AGRICULTURE. 

animals differ, somewhat in composition: phosj^hate of lime 
constitutes the largest proportion of the matter of dry bones ; 
the amount is from forty to sixty per cent, of their weight. 
Eight pounds of bone dust are equal in phosphates to 1000 
pounds of hay or wheat straw. 

The value of bones is nat dependent alone on the phos- 
phates, but partly upon the gelatine and other organic matters 
which enter into their composition : these latter operate in the 
same way as the other organic tissues of animals. Bones are 
prepared for manure by boiling, by maceration in sulphuric 
acid and water, and by grinding; the last of which methods is 
thought on all acounts to be preferable. In soils deficient in 
phosphates, bones are of great value ; and from the compara- 
tively small quantity of phosphates which most crops require, 
the effect of a large manuring with bone dust is manifest upon 
the land for many years; " 260 pounds of bone dust, (less than 
six bushels,) are sufRciej;jt to supply all the phosphates con- 
tained in the crops which are reaped from an acre during an 
entire fourshift rotation of turneps, barley, clover and wheat. 
Some lands remember a single dressmg for fifteen or twenty 
years. ' ' — [Johnston. 

The prolonged effect of bones is due to the organic as well 
as mineral matters. Bones should not be ground too fine: 
they are particularly applicable to turnep crops and pasture 
lands : the milk of cows contains about half a pound of phos- 
phates to every ten gallons; hence the necessity of these salts 
in the soil of pastures. Animal tissues, when used as manures, 
ought to be well covered with earth or ploughed under, in 
order to facilitate their decomposition, and at the same tims 
prevent the escape of the gases formed during this process. 

Solid excrements of animals. — Night soil, or human ordure, 
is a highly valuable fertilizer. It is best prepared for use by 
mixture with powdered charcoal, half burnt peat, or soil wliich 
is rich in vegetable matter ; quick hme has been used for the 



SCIENTIFIC AGRICULTURE. 197 

same purpose : but, although it destroys the odor, it dissipates 
at the same time a large portion of its ammonia. Dm'ing the 
decomposition of night soil, an evolution of carbonic acid, 
ammonia, sulphuretted and phosphuretted hydrogen takes 
place. After the escape of these gases, the odor ceases, and 
the remainder, when dried, constitutes what is sold in large 
cities under the name of poudrette. The odor of recent night 
soil may be destroyed, and the volatile elements retained, by 
adding to it gypsum or dilute sulphuric acid. This manure is 
used in the form of compost, and as a top dressing in the form 
of poudrette. 

The excrements of horned cattle are more valuable and 
enduring in their operation than those of the horse and sheep. 
It ferments more slowly on account of its smaller quantity of 
nitrogen; hence it retains its virtue longer, and produces a 
more lastingf effect on the soil. It is colder in its nature than 
that of the horse, which is owing partly to the amount of water 
it contains, and partly to its pecuhar constitution. 

The excrements of tlie horse abound more in nitrogen com- 
pounds than those of cattle. Even where both are fed upon 
the same food, those of the horse are more valuable than those 
of the cow. It begins to heat and ferment in a short time, and 
in two or three weeks, according to Johnston, loses nearly half 
its original weight On account of this rapid fermentation and 
the consequent loss of volatile matters, it should be mixed as 
soon as possible with charcoal, peat, sawdust, or earth rich in 
vegetable matters, or be sprinkled with gypsum or dilute 
.sulphuric acid. For the same reason, this kind of manure 
ought, contraiy to popular opinion, to be spread upon and 
ploughed into the soil before any signs of fermentation take 
place ; unless it is mixed with some other matters to form com- 
posts. From its tendency to ferment and develop heat, it is 
admirably adapted to enter into all composts. An additional 



198 SCIENTIFIC AGRICULTURE. 

quantity of water prevents too rapid fermentation and pre^, 
serves the virtues of this manure to a considerable extent. ^Jl 

The excrements of the hog are said to be a rich manure ; but 
they have a strong and unpleasant odor, and often impart a 
rank taste to the crops upon which they are used: for this 
reason it has been advised not to use them on crops, particu- 
larly of roots, which are designed for food. They are colder 
and less inclined to ferment than those of the cow, and should 
be combined with other manures or made into composts. 

The excrements of sheep form a richer and more fermentable 
manure than those of the cow : they are said to be most bene- 
ficial on soils which contain much vegetable matter, which 
absorbs the volatile matters which would otherwise pass off 
during fermentation. 

The value of all animal manures depends' much upon cir- 
cumstances, viz : the food upon which the animal is fed ; the 
age and condition of the animal ; the amount of labor he per- 
forms: the leneth of time and manner in which the manure is 
kept. Since, then, their value is affected by so many condi- 
tions, it is evident that no general conclusions can be drawn, 
which shall not be liable to exceptions ; and no set of analyses 
can furnish tables which shall in all cases agree. The following 
tables may be relied upon as being as nearl}'- correct as can be 
obtained, and sufficiently so for all practical purposes. 

Excrements of birds. — These are among the most powerful 
fertilizers. The excrement of pigeons is said to be particularly 
valuable to flax crops, for which it is held in high esteem in 
some parts of Europe. This, like most other manures, loses 
much of its value by being allowed to ferment without the 
admixture of some other matters to retain its volatile elements. 
The principal value of this, as well as the excrements of all 
birds, which have been analyzed and used as manures, is ^ 
dependent mainly on the large proportions of -ammonia and 
phosphates which they contain. The excrements of hens. 



SCIENTIFIC AGRICULTURE. lOD 

geese, turkeys and ducks, are of less value than those of the 
pigeons. 

Gtiano is the excrements of sea fowls, and is an earthy sub- 
stance of a grayish brown color : it is mostly found in Africa 
and South America. It is found on the islands and coasts of 
those countries, in latitudes where the weather is so dry that 
decomposition has proceeded slowly, and it has consequently 
accumulated in large quantities. Guano is said to be efficacious 
as a manure, applied to almost any crop : it is, however, accord- 
ing to Johnston, more advantageous to root crops than to grain 
or grass crops. It is conveniently applied as a top dressino-, 
mixed wth gypsum, wood ashes or powdered charcoal. Two 
or three hundred pounds to an acre is sufficient for a single 
dressino". 

The urine of men and animals is the most valuable and the 
most neglected of all manures. That of the cow and hoo- is 
said to be more valuable, because it contains more solid soluble 
matter than that of any other domestic animal. The efficacy 
of urine as a manure is due to the large quantity of urea, 
ammonia and j^hosphates, and con^quently of nitroo-en, which 
it contains. Recent urine generally exerts an unfavorable 
influence on growing vegetation ; it is most beneficially appHed 
after fermentation has fairly commenced, and before it reaclie.-^ 
the final stage of the process. — [Johnston. 

Decomposition is attended with a diminution of urea, and an 
increase of ammonia. It is important that the urine collected 
should be fermented in tightly covered cisterns to prevent the 
escape of volatile matters: it has been proposed to add gyp- 
sum, sulphate of iron, or sulphuric acid, to the fermentino- 
urine, in order to fix the ammonia; the mixture of vegetable 
mold with it has been also recommended as equally effective 
and more economical. The loss of manure in waste urine in 
densely populated countries and large cities, is immense,, as ie 
shown by the following calculation. 



200 SCIENTIFIC AGRICULTURE. 

[If we allow the quantity of urine voided by each individual to be 
600 pounds yearly, the city of Rochester, which contains 30,000 inhabi- 
tants, would furnish yearly 1,200,000 pounds, or 540 tons. This, esti- 
mated at the price of guano would be worth $21,600. Now if we esti- 
mate the number of horses and cows of the city to 500 of each, and 
that each animal voids as much urine as two persons, the amount would 
be 80,000 pounds, or 40 tons, which would be worth $1,600. Hero 
then is a loss, if we reckon guano at $40 per ton, of $23 200: or of 
manure enough to produce, in addition to the ordinar)' crop, over 
16,000 bushels of wheat in a single year. These calculations may not 
be correct, but they approximate this point sufficiently for our purpose.] 

VEGETABLE MANURES. 

Organic vegetable matters in various conditions, constitute 
the largest part of manure in use. The form in which they 
are prepared and applied has an important influence on their 
fertilizing effect. The principal difference between dry and 
green vegetable matter is, that the latter decomposes more 
rapidly and therefore acts more promptly. Unripe plants fur- 
nish a more valuable manure than ripe ones. 

Straw and chaff, when ploughed into the soil dry, are slow 
in decomposing, and act itODre slowly than when pre^dously 
fermented. The question of applying straw without previous 
decomposition, is, in practice only a question of time. It is 
doubtless true that it furnishes about the same amount of 
manure in both cases; but in the one case it has a more 
speedy and powerful, and in the other a more prolonged effect. 

Saw dust, is a cheap, and on some accounts a valuable ma- 
nure : it ferments slowly in the soil, and cannot, therefore, be 
much relied upon the first year or two. It is beneficial in ab- 
sorbing gases and liquid manures, and its effect is felt gradually 
by the soil as decomposition proceeds ; it is also beneficial to 
stifif clay land by rendering it more loose and light. 

Dry leaves and decayed wood, operate as manures in a man* 
ner similar to saw dust; they are however better fitted by 
decomposition in compost heaps. 



SCIENTIFIC AGRICULTURE. 201 

Oil calces, from cotton and linseed exhausted of tlieir oils, 
are valuable as fertilizers ; but tlieir value for fattening animals 
perhaps exceeds that as a manure, and may prevent their 
direct use for this purpose. 

Peat, is used with benefit on soils which are deficient in 
organic matters: it decomposes slowly, especially if sour or 
applied alone to a wet soil containing little lime. Its action, 
when properly decomposed and prepared, is the same as that 
of other vegetable matters : it usually contains more or less 
mineral and gaseous matters, which have their own peculiar 
operation ; but these are not to be considered as affecting the 
vegetable character of peat as a manure. On account of the 
slowness with which it decays, it should be mixed with Kme, 
gypsum, wood ashes, or some vegetable matter which decom- 
poses rapidly, such as farm-yard manure: swamp muck and 
humus are similar in properties to peat. 

Tanners^ harh is used as a manure, but is Hable to the 
same objection as peat in respect to its slow decay ; it is best 
brought into a state of fermentation by mixture with lime and 
farm-yard manure in composts. 

Soot, is a comphcated substance, as will be seen by refer- 
ence to the table : it contains many things necessary to vegeta- 
tion, and is a manure of some value ; but experiment has not 
3'et determined its precise character and operation. 

Cotton seed, in the cotton groining States, is a valuable ma- 
terial for manure: if its oil, which is about 20 per cent, of its 
weight, were first expressed, and the residual cake fed to stock, 
it would doubtless yield a better profit than when used as ma- 
nure without undergoing this process. It may be sowed upon 
the land and ploughed in at the close of autumn, where it will 
loose its germinating quality, and partly rot before spring : or 
it may be thrown in a heap alone or with lime, until its vitality 
is destroyed by the heat thus generated. 

Charcoal, on account of its power of absorbing gases and 
y 



202 SCIENTIFIC AGRICULTURE. " 

destroying offensive odors, is a valuable addition to the soil : 
its operation is not so direct as that of some other manures ; 
that is, it is not so useful on account of any element which it 
furnishes to plants, as by the intermediate office which it per- 
forms of absorbincr and retainino- in the soil those volatile mat- 
ters which plants require, and which would otherwise escape 
and be lost. It is beneficial as a top dressing, and as an 
ingredient in composts : it evolves carbonic acid in its decompo- 
sition, and is in this way directly useful to plants. Its power- 
ful antiseptic properties render it very beneficial to young and 
tender plants, by keeping the soil free of putrifying sub- 
stances which would otherwise destroy their spongioles and 
prevent their growth. 

Charcoal also deprives colored solutions of their coloring 
particles, and destroys the odor of putrifjang animal and vege- 
table substances : the odor of flowers and volatile oils is also 
destroyed by it. 

Cider CaTce, the refuse of apples after the cider is expressed 
from them, is valuable as a manure ; but the acidity which it 
contains should be neutralized by hme before being applied to 
the soil. 

Barley waste, the refuse barley after being malted and 
steeped for beer, contains a large amount of nitrogen, and is 
worth two and a half times its weight of manure as a fertilizer. 

Farm-yard manure. The manner and state in which farm- 
yard manure should be applied, has been a subject of much 
experiment, and controversy. The conclusions of Johnston in 
relation to this subject, appear rational and satisfactory. This 
kind of manure is made up of the sohd and Hquid excrements 
of animals together with straw and hay, some of which are in 
a state of decomposition, and the remainder fresh and un- 
changed. The question as to w^hich condition these manures 
should be used in, must depend upon circumstances. If the 
object is to furnish the greatest amount of organic matter to 



SCIENTIFIC AGRICULTTTRE. 203 

the soil, the sooner the manure is applied after it is made, the 
better this object is accomplished. On compact clays, the 
mixture of straw and coarse manure is beneficial, as it renders 
them looser and hghter, while the products of decomposition 
are more completely retained in the soil than they would be in 
a loose one. But coarse manures render loose soils more loose, 
and lose more of their elements in decomposing: for these 
reasons, compact fermented manures are preferable in such 
soils. For manuring crops which grow rapidly and attain 
maturity in a short time, well fermented manures and fine 
composts are felt more immediately and powerfully than re- 
cent ones. vSuch crops as turneps, buckwheat, clover, and 
many garden vegetables, might nearly attain maturity before 
decomposition would be sufficiently advanced in new and coarse 
manures to render them beneficial. When it is desired to force 
and quicken the growth of a crop, a well fermented, or fine 
heating manure should be used ; such as rich compost, bone 
dust, or the excrements of the horse and sheep. 

Top dressing for pastures, meadows and turnep crops, should 
usually be of the same kind as those just named. But farm- 
yard manure is not subject to any special law, but is to be used 
according to its quality and condition, and adapted to circum- 
stances. Veo-etable substances are all similar in their nature 
and operation, and are modified by conditions and circum- 
stances. They are all subject to the same laws, and their 
relative value depends on their constitution and adaptation to 
each particular case. 

GREEN MANURES, 

By green manures, is understood those plants which are 
grown for the purpose of being ploughed in and mixed with the 
soil before being harvested or used as food for animals. This 
plan of manuring is by no means of recent origin ; it was 
known and practiced among the Romans. The plants most in 
use for this purpose in the United States are red clover, buck- 



204 SCIENTIFIC AGRICULTURE. 

wlieat and grass in the form of green sward. Several other 
plants are used in Europe, viz., rape, lupine, vetches, rye, tur- 
nep, carrot and beet tops, borage, spurry, sea weeds and fresh 
water plants. 

The advantages of green manures, according to Johnston, 
are, — 1. They undergo decomposition sooner than dry vegeta- 
ble matter, and consequently become sooner available for the 
food of succeeding crops. 2. The nitrogen and carbon which 
they contain, if allowed to decay in the open air, are lost; 
while if the plants had been buried, before decay, these gases 
would have been mostly retained in the soil for the use of suc- 
ceeding crops. 3. By ploughing in a crop of plants, the or- 
ganic matter is more equally distributed through the soil than 
could be done by any other means. 4. Green manures are 
available where other manures are scarce, and in soils deficient 
in organic matter. 5. The plants used as green manures, bring 
up towards the surface by their roots, matters which had sunk 
into the soil too deep to be of much sendee. 6. It restores to 
the soil all it took from it, in a more soluble and available con- 
dition ; and in addition to this, those gases also which the plants 
extracted from the air during growth. 7. A green crop yields 
more manure than the same crop could do in any other form. 
8. A grain crop is greater on the same field when green, than 
when fermented manures are used. The best plants for 
green manures are those which grow the fastest, produce the 
most vegetable matter, and with the smallest expense. 

Sufficient seed should be sown, that the plants may cover 
the ground completely ; the crop should be ploughed in before 
the time of full blowing, because the flowers give ofif nitrogen, 
which is wasted in the air. Agriculturists agree that a second 
and third crop of gTeen plants still continue to improve the 
soil; but there must be a limit, beyond which this practice 
cannot be carried with benefit and profit. Green manunng 
might perhaps secure a field against barrenness for an indcfi- 



i 



SCIENTIFIC AGRICULTURE. 205 

nite period of time, providing nothing was taken off: but if a 
crop was occasionally carried away, it must of course be im- 
poverislied to the amount of what is taken off in mineral 
matters. It is probably true that lands in a state of nature, 
which are covered with forest trees or other vegetation, never 
become barren. 

The soil may in time become deficient in a particular mineral 
element which the incumbent plants require : but when these 
die out, others immediately spring up by a natural rotation, 
and, requiring elements slightly different from the first, grow 
as luxuriantly as they did. Thus one race of plants succeeds 
another, each in turn exhausting the soil of certain elements, 
and leifving it richer in others. The question may arise. What 
becomes of the mineral elements which are lost, if nothing is 
taken off the soil, since they do not escape into the air? The 
probability is, they sink down deeper and deeper into the soil 
in the form of soluble salts, until beyond the reach of the 
roots of plants. 

IMPROVEMENT OF THE SOIL BY PASTURE. 

Pasture ma}^ be either temporary or peniianent. Tempo- 
rary pasture consists in laying down a field to pasture for one, 
two or three years, or more. The soil is benefitted by pasture 
in several different ways. The roots of the grass which remain 
furnish a large amount of organic matter, which, to a soil poor 
in this constituent, is of great benefit. Land which lies several 
years will be more benefitted than when it lies but a single 
year : but the first year enriches it more than any succeeding 
one. The result to the land will be nearly the same, whether 
the grass be mown or eaten off by the stock. " That farming 
is the most economical, where the land will admit of it, which 
permits the clover or grass to occupy the land for a single 
year only." 

Permanent p)asture consists in the suspension of grain crops, 
and the occupation of the land by gTass or clover, for an indefi- 



206 SCIENTIFIC AGRICULTURE. 

nite period of time. Besides the benefit wMcli the soil derives 
from the organic matters left in it, some of its mineral con- 
stituents are, by the action of air, moisture, and the roots of 
the grass, brought into a more soluble state to be used by 
succeeding crops. Another advantage of pasture, especially 
on stiff clay soil, is that it renders it more loose and friable. 
On dry, sandy soils, pasture is beneficial, by retaining the 
moisture longer, and also the dry organic matters and fine 
sand upon the surface, Avhich would otlierwise be blown away 
by the winds. Insects perform a part in improving pasture 
lands, which is by no means insignificant. 

They subsist upon the organic matters of the soil, which 
they bring into a minute state of division and deposit on the 
surface as they ascend by night through their holes. They 
furnish also, considerable organic matter, which is rich in 
nitrogen, by the death and decay of their own bodies. Thus 
these earth worms and insects, in the lapse of a few years, 
furnish a vast amount of the richest manure without the 
smallest expense. The time which land may lay in pasture 
and still increase in richness, must have a limit, — and this 
depends upon the quality of the soil and the kinds of grass 
which occupy it. 

The soil will require an occasional top dressing, or the pas- 
ture wull deteriorate : on account of the exhaustion of certain 
elements in the soil, grasses, as well as forest trees and other 
plants, tend to a natural rotation ; one species, after flourishing 
a few years, begins to decline and finally dies out, and is 
replaced by another, and this, in time, by another, — and so on, 
indefinitely. All pasture lands Avhatever, which are arable, 
can, after a series of years, be subjected to grain crops; and 
this in most cases would doubtless be expedient. This, how- 
ever, must be determined, in each particular case, by an appre- 
ciation of all the circumstances and conditions. 



CHAPTER yi. 



MINERAL MANURES. 

Mineral manures are di\ided, for the sake of convenience, 
into saline and earthy ; the former including pure salts whose 
composition is exactly known, such as common salt and car- 
bonate of soda; and the latter including the various earthy 
matters used to ameliorate the soil, such as lime, wood ashes, 
and marl. The mineral manures are all supposed to have a 
specific mode of action, which is peculiar to each respectively : 
the theory of their action, however, as fertilizers, cannot, for 
want of space, except in a few cases, be detailed. But few, 
comparatively, of the known mineral fertilizers are in common 
use, and those only will be described. 

SALINE manures. 

Carbonate of soda. — This salt, according to Johnston, is 
beneficial on lands abounding in sulphate of iron, or overgrown 
\n.\h mosses and other noxious vegetation ; and also as a top 
dressing to fields of young grain, and wherever wood ashes 
would be useful. It is said to be peculiarly beneficial to the 
strawberry. From forty to sixty pounds may be applied to 
an acre, either in powder mixed with other manure, or in 
solution. 

Suljyhate of soda, or Olaiiher^s salt, has been used with 
much benefit on fruit trees, rye, beans, beets, and some other 
crops. The quantity used should be at least one hundred 



208 SCIENTIFIC AGRICULTURE. 

pounds per acre, either in solution or in powder just before a 
rain. [It must not be inferred, that this, or any other manure, 
because it is recommended for a particular species of plants, 
is not therefore adapted to the growth of others ; but those only 
are mentioned, upon which they have been tried sufficiently to 
warrant a conclusion as to their efficacy.] 

Sulphate of magnesia, or epsom salts, is said to be useful to 
young crops of wheat, clover, peas and beans : one or two 
hundred pounds to an acre should be used. 

Suljjhate of lime, or gyi^sum. — This salt of lime, usually 
called " plaster," has been long- known and much employed as 
a fertilizer on almost all crops and soils. It requires much 
water for its solution. The beneficial operation of gypsum is 
supposed to depend upon several circumstances. This, like all 
the sulphates, furnishes sulphur, which is important in the 
nutrition of plants, especially those of the leguminous arder. 
Gypsum prevents the escape of ammonia Avhich is deposited 
in the soil by rain, and evolved by the decomposition of ani- 
mal and vegetable matters. In soils deficient in Hme, it supplies 
this element in an available state for their nutrition. It has 
been thought to operate most beneficially on red clover and 
Indian corn. 

Nitrate of soda is on some accounts a good fertilizer ; it has 
not come into general use, and is not as well understood in its 
relations to soils and to plants as it should be. Several results 
are theoretically attributed by Johnston to the action of the 
nitrates on vegetation. 1. They give a dark green color to 
the leaves. 2. They hasten and sometimes prolong the growth 
of vegetation. 3. They increase both the straw and the grain 
of the cereals. They impart a sahne taste to hay and 
straw, which causes cattle to eat them with more avidity. 
5. Grain which has been manured Avith the nitrates yields 
more bran and less flour than those manured with other salts. 
The nitrates increase the oat crop ; they should not, however, 



SCIENTIFIC AGRICULTURE. 209 

be used for any crop on land which is already disposed to 
produce too much straw. They are exceedingly soluble, and 
are for this reason not so beneficial on loose, hght soils, because 
more easily washed away than on close, compact soils : for the 
same reason they produce httle effect after the first year. 
They furnish a large amount of nitrogen, and are most bene- 
ficial to poor soils wliich are deficient in organic matters. 

All organic compounds containing nitrogen, evolve the 
whole of that element when acted upon by acids, alkahes and 
heat: it is only when there is a deficiency of water or of its 
elements^ that cyanogen and other nitrogenized compounds are 
produced. Ammonia is therefore the most stable compound 
of nitrogen : nitrogen has a stronger affinity for hydrogen than 
for any other body. — [Liebig. 

Chloride of sodium, or common salt, has been used with 
various results as a fertihzer. Plants require for their growth 
both of the elements of common salt, viz. — chlorine and soda; 
and in soils which are deficient in one or both of these ele- 
ments, there can be no doubt as to its efficacy ; but in a soil 
which contains them in sufficient quantity in a soluble state, it 
cannot be expected that this salt will be of any service. It is 
most likely to prove beneficial on lands lying remote from the 
sea, and which, consequently, would be more apt to require it. 
This salt is of more benefit to green crops than cereals ; and 
also to hasten and increase the growth of the herbage of plants 
than the seeds. 

The chlorides of lime and 7nagnesia contained among the 
refuse of chemical manufactories, are also used as manures 
yA\h good effects. The chlorides are destructive to both ani- 
mal and vegetable life, when used in large quantity; they 
have consequently been used to destroy weeds, worms and 
insects in the soil. 

The silicate of potash and soda, and the various salts of 
ammonia are, without question, powerful fertiHzers, particu- 



210 SCIENTIFIC AGRICULTURE. 

larly on tlie grasses; but tliey are not in general use, on 
account of their high price, as well as doubtful reputation 
among those practical men who have not tested them. 

Arsenic has been used as a manure with benefit, — and also 
in solution for soaking seeds, especially corn, in order to poison 
crows and other birds which pull the corn : by this means 
partridges have been poisoned, and the persons who have 
eaten them have been poisoned also. 

EARTHY MANURES. 

Wood ashes. The ashes of wood and all other vegetable 
matter, contain various proportions of several different salts, ojl 
of which are necessary to the growth of plants. The foUoAving 
table presents an analysis of the ashes of the red beech and 
oak, by Sprengel. 



Silica, 


5.52 


26.95 


Alumina, 


2.33 




Oxide of Iron, 


3.77 


8.14 


Oxide of Manganese, 


3.85 




Lime, 


25.00 


17.38 


ISIagnesia, 


5.00 


1.44 


Potash, 


22.11 


16.20 


Soda, 


3.32 


6.73 


Sulphuric Acid, 


7.64 


3.36 


Phosphoric Acid, 


5.62 


1.92 


Chlorine, 


1.84 


2.41 


Carbonic Acid, 


14.00 


15.47 



100. 100. 

It will be seen by the table, that one kind of ash is richer 

in one element, and another in some other element: the value 

of each must be estimated accordingly. The ashes of the oak 

and beech, both contain more lime than they do potash, and 



SCIENTIFIC AGRICtTLTURE. 211 

would therefore be as efficacious on a soil deficient in lime, as 
on one deficient in potash. We see, then, that, contrary to 
popular opinion, the utility of this manure does not depend 
solely upon the action of potash, but on several other elements 
also. 

Ashes, as a general rule, are used with benefit on the 
grasses, leguminous and Indian corn crops. They may be 
mixed with an equal quantity of gypsum or bone dust, and 
applied to the amount of ten to thirty bushels to an acre ; or, 
if the ashes have been leached, fifty, sixty, or a hundred 
bushels, may be used to an acre. According to Johnston, only 
about one-fifteenth part of the weight of ashes are immediately 
soluble ; their effects are therefore more permanent than those 
of any of the soluble saline manures, being felt by the land for 
more than ten years. 

The following mixture is said to be nearly equal in efficacy 
for a year or two, to one ton of wood ashes. 

Crude potash, 60 pounds. 

Crystalized carbonate of soda, 60 " 
Sulphate of soda, 20 " 

Common salt, , 20 " 



160 

Leached ashes are nearly destitute of potash, and cannot, of 
course, supply this substance to vegetation; they are said, 
however, to be of service to oat crops in particular, and are 
beneficial to clay soils. The ashes of coal, jpeat, turf, straw 
and cane are also valuable as fertilizers, according to their 
constitution and the crops to which they are applied. 

Exhausted ley of asheries and soap factories, although de- 
prived of nearly all of its potash, still contains some of this 
element, and considerable soda and nitrogen, which elements 
constitute it a valuable fertilizer; five gallons of this liquid are 
estimated to contain as much potash and soda as three barrels 
of ashes. 



212 SCIENTIFIC AGRICULTURE. 

Coal loaste also, from the stoves and grates where stone 
coal has been burnt, contains potash, carbon, silica, iron and 
other matters which are beneficial to land, and can be obtained 
in considerable quantities in cities free of cost. It would be 
applicable to stiff clay soils in particular, but to others also. 

Crushed or 2)idverized rocks of various kinds could be used 
with the same benefit and in the same cases, according to their 
elementary composition, as other mineral manures: crushed 
granite would furnish a considerable amount of potash ; it is 
easily ground after being heated to a red heat. Crushed trap 
contains much lime, and is a good manure : crushed lavas are 
also valuable on most soils. 

Marl. The composition and other chemical characters of 
marl have been described : it consists of lime, clay, and often 
sand, shells, and other matters. The object and effect of 
marling are similar to those of liming land. ^Marl should be 
used according to its constitution ; clay marl should usually be 
put on sandy soils, and lime or sandy marl on clay soils. The 
best time for laying on marl is at the end of autumn, so that 
it may be pulverized by frosts during the winter. Boussin- 
gault says, land which contains ten per cent, of carbonate of 
lime can dispense with marl. 

The effect of marl is not unlimited, but, hke lime, requires 
to be repeated once in 10 or 12 years. With regard to the 
quantity of marl which should be used to an acre, we must be 
governed by the same rational considerations as in the use of 
all other manures ; viz., it should be apphed where it is re- 
quired, and in quantity equal to the demand of the soil. The 
opinions of practical men vary greatly on this subject : accord- 
ing to Johnston, ten or fifteen, to one hundred and twenty tons 
are used to an acre ; while Boussingault says, " allowing the 
broadest margin, and judging from the composition of the ashes 
of the plants of ordinary crops, we can see that the quantity 
of three and a half bushels of marl of the usual composition 



SCIENTIFIC AGRICULTURE. 213 

per acre, which is assumed as the average quantity to be laid 
on, is vastly more than can be absolutely necessary." 

This discrepancy has arisen partly from the extravagant 
notions about the virtues of marl, and partly from the nature 
of the marl and the soils to which it has been apphed by differ- 
ent experimenters. 

Chalk is much used as a fertilizer in some parts of Europe 
where it is cheap and abundant ; but, from its scarcity and 
price, it can never be expedient to use it in this country while 
Tve have such an abundance of Hme in various other forms. 
When used, it is subject to nearly the same laws as hme and 
marl. -Its composition varies; some specimens contain more 
phosphate of lime, magnesia and silicates, than others. Ehren- 
berg has made the remarkable discovery, that chalk to a con- 
siderable extent, is composed of the shells or skeletons of 
marine microscopic animals. 

Sea-side sand^ which contains muck, fragments of shells, 
animal matter, several salts, &c., is a valuable manure. 

Vitriolic ashes are the residues from copperas manufactories : 
mixed with peat or wood ashes they form a valuable addition 
to the soil. 

Lime. The chemical and physical properties of hme have 
already been described, and it remains for us to examine briefly 
the principles of its adaptation to the soil as a fertihzer. Much 
discussion has been had, and many long essays written on this 
subject; but no chemist claims for this substance any excep- 
tion to general chemical laws, or attributes to it any action 
more specific than that of any other manure. There is no 
doubt that all our present knowledge of lime as a manure, 
can be expressed in a few known and plain principles: we do 
not assume that all is known about lime that may be known at 
some future time, but that the facts can be much more briefly 
and perhaps more clearly set forth than is done by most wri- 
ters on agriculture. 



214 SCIENTIFIC AGRICULTURE. 

Lime is perliaps tlie most important mineral used as a ma- 
nure. When applied to a soil entirely destitute of lime, the 
quantity Avill necessarily be larger than at subsequent periods. 

The quantity used must be determined, as in all other cases, 
by circumstances. No general rule can be given for its use, 
but each one must judge from the facts in the case and pro- 
ceed accordingly. Johnston says, " if we suppose one per cent, 
to be necessary, then upwards of 300 bushels of slaked lime 
must be mixed with a soil six inches in depth, to impart to an 
acre this proportion." On wet, peaty, marshy, or clay soils, 
more lime will be necessary than on dry, sandy and loose soils ; 
on soils which contain much organic matters also, more may be 
used than on those nearly destitute of them. It is considered 
better economy to apply lime in smaller quantities and at 
shorter intervals, than to use in large quantities at more dis- 
tant periods. 

Caustic lime should be apphed to marshy and clay soils im- 
mediately after slaking : when allowed to slake in the open air 
spontaneously, Avithout the use of water, it is more mild, and 
better adapted to grass lands and young crops ; but when ap- 
plied to naked fallow and mixed with the soil, it may be used 
in eitlier state. Burned Hme is well adapted to the compost 
form of manures. As quick lime dissipates the ammonia of 
fermenting manures in the soil, it ought not to be applied at 
the same time, nor to come in immediate contact with them : 
it is best applied usually in the fall, or as long as possible be- 
fore the next crop is sown. 

These principles apply only to causitc lime : unburned lime, 
marl, gypsum, chalk, and composts containing lime, may be 
apphed at any time. Lime, in order that it may produce its 
full effect and most lasting benefit, should be kept near the 
surface. This may be done by sub-soil ploughing, by which 
the lime is thrown up to the surface ; and also by sowing deep 
rooted crops, which will reach it after it has sunk too deep to 



SCIENTIFIC AGRICULTURE. 215 

benefit others of shorter roots. The amount of lime in the 
soil gradually diminishes from several causes, when it is not 
occasionally replenished : it is removed to a small extent with 
the annual harvests, and by assuming new forms by chemical 
action; a portion is also carried away in solution with the 
water which falls by rain and filters through both the surface 
and subsoil. 

The beneficial effects of lime, although more permanent, are 
not felt as soon as those of some other mineral manures : it is 
of Kttle service on soils deficient in organic matter. The length 
of time which lime shows its effects upon the crops and soil, is, 
according to circumstances, from ten to thirty years. Its use 
is sometimes attended by unfavorable results when not judi- 
ciously used : light, loose soils are rendered too loose ; and the 
growth of certain noxious weeds favored by its presence : an 
over-dose destroys too much organic matter, hardens certain 
soils, and injures the spongioles of young plants. It is said to 
operate injuriously upon flax, by causing tenderness of its cor- 
tical fibre. 

These remarks on the use of lime as a manure, are conden- 
sed from Johnston, who has given perhaps the best treatise on 
lime extant. As the subject is both important and interesting, 
it may be well to recapitulate briefly. 
Recapitulation. 

1. Lime increases the fertiUty of soils deficient in this element. 

2. It causes the soil to produce grain which yields more flour 
and less bran, and improves the quality of all other crops. 

3. It increases the effect of other manures by hastening 
decomposition. 

4. It destroys noxious insects and worms. 

5. It destroys noxious weeds and mosses, and gives rise to 
sweet grasses and herbage. 

6. It prevents smut in w^heat and other crops. 

7. It hastens the maturity of the crop. 



21G SCIENTIFIC AGRICULTURE. 

8. It neutralizes the acidity of soar soils and renders tliem 
productive. 

9. It makes cold wet soils dryer and warmer. 

10. It renders tight stiff clays loose and friable. 

11. It destroys noxious gases and promotes health. 

12. It stiffens loose sandy soils. 

13. It brino-s inert oro-anic matters into a state of fermen- 

O O 

tation. 

14. It causes the evolution of carbonic acid. 

1 5. It serves directly as the food of plants. 

16. It causes the formation of several salts in the soil. 

COMPOSTS. 

It was formerly supposed, that great advantage was derived 
from the combination of several diffei'ent substances too-ether, 
and forming what are called composts. The recipes for these 
compounds are numerous, and go to prove that the discovery 
of a good compost requires but little scientific or practical skill. 
When a compost heap is made up of several materials which 
are all separately good manures, it follows of necessity that 
the resulting compound must be a good fertilizer. But it is 
impossible to supply any more in this way than if these seve- 
ral ingredients were applied to the soil separately. And a 
little knowledge of chemistry will show that by tliis means, 
no new elements can be generated. Neither can any new pro- 
perty be developed which could not be done by their separate 
action. We see that whenever a substance which has little or 
no fertilizing power, is in this way manufactured into a good 
manure, it is done at the expense of some powerful fertilizer 
which is diluted by the mixture, and consequently loses just 
as much of its efficacy as the other gains. Thus, although 
this process serves to dilute and extend manures which are 
too powerful or too expensive, it absolutely supplies none. 

Now, although it is evident that this method does not aug- 



31 



f5CIENTIFIC AGRICULTURE. 217 

ment in the slightest degree, our quantity of available ma- 
nure, — yet it has several advantages. Caustic lime and wood 
ashes are sometimes too strong for young and tender vegeta- 
tion; and when this is the case, the object of their use is 
much better attained by mixing and diffusing them through 
some other substance, such as saw-dust, sand, barn manure or 
humus, or allowing them to lie in a heap together with any 
vegetable matters, such as leaves, straw, chaif, rotten wood or 
turf; or with animal matters ; until decomposition is completed. 

Another advantage is, that a manure which is valuable and 
scarce, as guano, poudrette, and some chemical salts, may be 
extended by mixture so as to be applied to a much larger space" 
than would be practicable if used singly. Thirdly, this mode 
enables the agriculturist to spread his manure on the soil more 
even and uniformly. And lastly, by making compost we are 
enabled to hasten the final decay of animal and vegetable 
matters, so as to gain considerable time. By mixing quicklime 
with barn manure, straw, leaves, &c., decomposition goes on 
more rapidly, and these substances are transformed to availa- 
ble manures in a comparatively short space of time. But 
much discretion is necessary in this respect, otherwise some 
valuable elements are wasted ; the object is to fix and retain 
the volatile elements — and not to dissipate them. A great 
objection to composts is, the amount of labor required in ma- 
king, turning, and transporting them to the fields. 

No definite formula can with any propriety be given for 
making composts, as the agTiculturist must determine for him- 
self in each particular case, as to what elements his fields most 
require, and also his time and the resources at his command. 
With these considerations, and an adequate knowledge af his 
business, he will be able to make a more judicious disposition 
of his manures than by the aid of any prescribed rules which 
can be laid down in books. 

10 



CHAPTER YII. 



TABLE OF THE COMPARATIVE VALUE OF MANURES, 

FROM ANALYSES BY MESSRS. PAYEN AND B0U8SINGAULT. 



Kind of Manure. 



Farm-yard manure, 
Water from do. 
Wheat straw, 
Rye straw, 
Oat straw, 
Barley straw. 
Wheat chaff. 
Pea straw, 
Buckwheat straw, 
Dried potato tops. 
Oak leaves. 
Beech leaves, 
Burnt sea weed, 
Oyster shells, 
Sea-side marl. 
Oak saw-dust, 
Oil cake of linseed, 
Refuse of cider apples. 
Cow's ordure, 
Cow's urine. 
Excrements of horse, 
Urine of do. 

Excrements of pig, 





Nitrogen in 


Qual'y accor- 1 


Equival'nt 


79.3 


100 of matter. 


ding to state. 


accord, do. 


Dry. 


Wet. 


Dry. 


Wet. 


Dry. 


Wet. 


1.95 


0.41 


100 


100 


100 


100 


99.6 


1.54 


0.06 


78 


2 


127 


. 69 


19.3 


0.30 


0.24 


15 


60 


650 


167 


12.2 


0.20 


0.17 


10 


42.5 


975 


235 


21.0 


0.36 


0.28 


18 


70 


542 


143 


11.0 


0.26 


0.23 


13 


57.5 


750 


174 


7.6 


0.94 


0.85 


48 


212.5 


207 


47 


8.5 


1.95 


1.79 


100 


447.5 


100 


22 


11.6 


0.54 


0.48 


27 


120 


301 


83 


12.9 


0.43 


0.37 


22 


92.5 


453 


108 


25.0 


1.57 


1.18 


80 


293 


125 


34 


39.3 


1.91 


1.18 


7S 


294 


102 


34 


3.8 


0.40 


0.38 


20 


95 


488 


105 


17.9 


0.40 


0.32 


20 


80 


488 


125 


1.0 


0.52 


0.51 


26.5 


128 


377 


78 


26.0 


0.72 


0.54 


36 


135 


256 


74 


13.4 


6.00 


5.20 


307 


1300 


33 


8 


6.4 


0.63 


0.59 


32 


147 


309 


68 


85.9 


2.30 


0.32 


117 


80 


84 


125 


88.3 


3.80 


0.44 


194 


110 


51 


91 


75.3 


2.21 


0.55 


113 


137.5 


88 


73 


79.1 


12.50 


2.61 


64a 


652.5 


15.5 


15.3 


8.14 


3.37 


0.63 


172 


157.5 


68 


63 



SCIENTIFIC AGRICULTURE. 



219 







Nitrogen in 


Qual'y accor- 


Equival'nt 


Kind of Manure. 


ai 

63.0 


100 of matter. 


ding to state. 


accord, do. 




Dry. 


Wet. 


Dry. 
153 


Wet. 


Dry. 


Wet. 


Excrements of slieep, 


2.99 


1.11 


277.5 


36 


Do. of goat, 


46.0 


3.93 


2.16 


201 


540 


50 


18.5 


Poudrette, 


12.5 


4.40 


3.85 


225 


962 


44 


10.3 


Urine of public vats, 


9.6 


17.56 


16.83 


900 


4213 


11 


2.3 


Excrements of pigeons 


9.6 


9.02 


8.30 


462 


2075 


21.5 


5.0 


Guano, 


19.6 


6.20 


5.00 


823 


1247 


31.5 


80 


Dr^ed muscular flesh, 


Q.5 


14.25 


13.04 


730 


3260 


13.5 


3 


Liquid blood, 


81.0 




2.95 


795 


736 




13.3 


Fresh bones, 


30.0 




6.22 




1554 




6.5 


Dregs of glue. 


33.6 


5.63 


3.73 


288.4 


933.5 


35 


11 


Sugar refiners' scum, 


67.0 


1.58 


0.54 


81 


134 


127 


75 


Horn shavings. 


9.0 


15.78 


14.36 


809 


3590 


12.3 


3.0 


Wood soot^ 


5.6 


1.31 


1.15 


67 


287.5 


149 


35 



TABLES OF ANALYSIS. 

Tables showing the relative proportions of inorganic com- 
pounds in the ashes of several cultivated plants. 

The tables are taken mostly from Prof. Johnston's Agricul- 
tural Chemistry, — and are supposed to be nearly correct: 
analysis of diflPerent varieties and qualities of the same plants, 
vary slightly; but still, for all practical purposes, the tables 
here given are sufficiently accurate, b.eing probably as near the 
real constitution of them as it is possible to obtain. 

ASH OF WHEAT. 

According to Sprengel's analysis, 1000 lbs, of wheat leave 
11.77 lbs. of ashes, — and 1000 lbs. of straw leave 35.18 lbs. 
of ash, after burning. 



This ash consists of 

Potash, 
Soda, 
lime, 
Magnesia, 



Grain of wheat 
2.25 lbs. 

2.40 

0.96 

0.90 



Straw of wheat. 
0-20 lbs. 
0.59 
2.40 
0.32 



220 SCIENTIFIC AGRICULTURE. 

ASH OF WHEAT — Continued, 

Grain of Wheat. Straw of Wheal. 
Alumina and a trace of Iron, 0.26 lbs. 0.90 lbs. 

Silica, 4.00 28.70 

Sulphuric acid, 0.50 0.37 

Phosphoric acid, 0.40 1.70 

Chlorine, 0.10 0.30 





11.77 lbs. 35.18 lbs. 


ASH 


OF BARLEY. 




100 of grain of barley leaves 23.49 Ibs.- 


—1000 lbs. of straTf 


52.42 of ash. 


Grain. 


Straw. 


Potash, 


2.78 


1.80 


Soda, 


2.90 


0.48 


Lime, 


1.06 


5.54 


Magnesia, 
Alumina, 


1.80 
•0.25 


0,76 
1.46 


Oxide of iron, 


a trace 


0.14 


Oxide of manganese. 


0.20 


Silica, 


11.82 


38.56 


Sulphuric acid. 
Phosphoric acid. 
Chlorine, 


0.59 
2.10 
0.19 


1.18 
1.60 
0.70 




23.49 lbs. 


52.42 lbs. 


ASH 


[ OF OATS. 




1000 lbs. of the grain of oats contain 


25.80 lbs. — ^and of 


straw, 57.40 lbs. of ash. 


Grain. 


Straw. 


Potash, 


1.59 


8.70 


Soda, 


1.32 


0.02 


Lime, 


0.86 


1.52 


Magnesia, 
Alumina, 


0.67 
0.14 


0.22 
0.06 



SCIENTIT'IC AGRICULTURE. 221 



ASH OF ( 


OATS — Continu 


•ed. 




Grain. 


Straw, 


Oxide of iron, 


0.40 


0.02 


Oxide of manganese. 


0.02 


Silica, 


19.76 


45,88 


Sulphuric acid. 


0.35 


0.79 


Phosphoric acid. 


0.70 


0.12 


Chlorme, 


0.10 


0.05 




25.80 lbs. 


57.40 lbs. 



ASH OF RYE. 

1000 Jbs. of rye stra-w contain 27.93 lbs., and of grain 10.40 
ibs. of ash. 





Grain. 




Straw. 


Potash, 


5.32 




0.32 


Soda, 






0.11 


Lime, 


L22 




1.7s 


Magnesia, 


L78 




0.12 


Alumina, 


0.24 




25 


Oxide of iron. 


0.42 




Vfc'W V 


Oxide of manganese. 


, 0.34 






Silica, 


1.64 




22.97 


Sulphuric acid, 


0.23 




1.70 


Phosphoric acid. 


0.46 




0,51 


Chlorine, 


0.09 




0.17 




10.40 lbs. 




27.93 1 


ANALYSIS OF PEAT BY BOUSSINGAULT, 


Sihca, 




65,5 




Alumina, 




16.2 




Lime, 




8.0 




Magnesia, 




0.S 




Oxide of iron, 


1 ■ 


8.7 




Potash and Soda, 


2.3 





222 



SCIENTIFIC AGRICULTURE. 



ANALYSIS OF PEAT, BY BoussiNGAULT — Continued, 

Sulphuric acid, 5.4 

Chlorine, 0.3 



100.0 



ANALYSIS OF COAL ASHES BY BOUSSINGAULT. 

Argillaceous matter insoluble in acids, 62 

Alumina, 5 

Lime, 6 

Magnesia, 8 

Oxide of manganese, 3 

Oxide and sulphuret of iron 16 



100 



ASH OF THE BEAN AND PEA. 



1000 lbs. of seed and straw,, dried, contain — 







Field 


Bean. 


Field 


Pea. 






Seed. 


Straw. 


Seed. 


Straw. 


Potash, 




4J5 


16.56 


8.10 


2.35 


Soda, 




8.16 


0.50 


7.39 




Lime, 




1.65 


6.24 


0.58 


27.30 


Magnesia, 




1.58 


2,09 


1.36 


3.42 


Alumina, 




0.34 


0.10 


0.20 


0.60 


Oxide of iron. 




0.07 


0.10 


0.20 


Oxide of manganese. 




0.05 




0.07 


Silica, 




1.26 


2.20 


4,10 


9.96 


Sulphuric 


acid. 


0.89 


0.34 


0.53 


3.37 


Phosphoric 


! acid. 


2.92 


2.26 


1.90 


2.40 


Chlorine, 




0.41 


0.80 


0.38 


0.04 



21.36 31.21 24.64 49.71 

ASH OF THE TURNEP AND POTATO. 

10.000 lbs. of the roots, stalks and ieaves, when takes 
beftwre dryings contain — 



SCIEKTinC AGRICULTURE. 



223 





Potato. 
Roots. Tops. 


Turnep. 
Roots. Leaves^ 


Potash, 


40.28 


81.9 


23.86 


32.3 


Soda, 


23.34 


00.9 


10.48 


22.2 


Lime, 


3.31 


129.7 


7.52 


62.0 


Magnesia, 


3.24 


17.0 


2.54 


05.9 


Alumina, 
Oxide of iron. 


0.60 
0.32 


00.4 
00.2 


0.36 
0.32 


00.3 
01.7 


Oxide of manganese, 










Silica, 


0.84 


49.4 


3.88 


12.8 


Sulphuric acid. 


5.40 


04.2 


8.01 


25.2 


Phosphoric acid. 
Chlorine, 


4.01 
1.60 


19.7 
05.0 


3.67 
2.39 


9.8 

8.7 



82,83 308.4 63,03 

ASH OF THE CARROT AND PARSNEP. 



180.9 







Carrot. 


Parsnep. 


Potash, 




63.33 


20.79 


Soda, 




9.22 


7.02 


Lime, 




6.57 


4.68 


Magnesia, 




3.84 


2.70 


Alumina, 




0.39 


0.24 


Oxide of iron. 




0.33 


0.05 


Oxide of manganese. 


0.60 




Silica, 




1.37 


0.84 


Sulphuric acid, 




2.70 


5.40 


Phosphoric acid, 




6.14 


4.01 


Chlorine, 




0.70 


1.60 




66.19 


82.83 


ASH OF 


GRASS 


AND CLOVER. 




lbs. of dry hay and cloy 


er contain — 








Rye Grass. 


Red Clover, 


Potash, 




8.81 


19.96 


Soda, 




3.94 


5.29 



224 SCIENTIFIC AGRICULTURE. 



ASH OF GRASS AND 


CLOVEB — ( 


Continued. 


Lime, 


7.34 


27.80 


Magnesia, 


0.90 


3.33 


Alumina, 


0.31 


0.14 


Oxide of iron. 






Oxide of manganese. 






Silica, 


27.72 


3.61 


Sulphuric acid, 


3.53 


4.47 


Phosphoric acid. 


0.25 


6.57 


Chlorine, 


0.06 


3.62 



52.86 74.78 

The practical inferences from these tables are, — first — the 
kind of soil in which each will grow best, — second — the kind 
of inorganic matter necessary to be supplied artificially, — 
third — their nutrient properties, and the kmd of stock they 
are best adapted to nourish. 

The following table from " Liebig's Agricultural Chemis- 
try," shows the relative proportions of potash, lime and silica 
in several cultivated plants. 

SILICA PLANTS. 





Salts of Potash 


Salts of Magne- 








and Soda, 


sia and Lime. 


Silica. 


Oat straw and seeds. 




34.00 


4.00 


62.0(^ 


Wheat straw, 




22.50 


7.20 


61.50 


Barley straw and seeds, 


19.00 


25.70 


65.30 


Rye straw. 




18.65 


16.52 


63.89 


Good hay, 




6.00 


34.00 


60.00 




LIME PLANTS. 






Tobacco, 




24.34 


H7.44 


8.30 


Pea straw. 




27.82 


63.74 


7.81 


Potato tops, 




4.20 


61.40 


63.40 


Meadow Clover, 




39.20 


56.00 


4.90 


Com stalks, 




72.45 


6.50 


18.00 



SCIENTIFIC AGRICULTURE. 225 

POTASH PLANTS — Continued. 

Turneps, 81.60 18.40 

Beet roots, 88.00 12.00 

Potatoes, 85.81 14.19 

The following table from Johnston, shows the composition 
of the ashes of several grains without the straw. 





Wheat. 


Oats. 


Barley. 


Rye. 


Potash and soda. 


37.72 


19.12 


20.70 


37.21 


Lime, 


1.93 


10.41 


3.36 


2.92 


Magnesia, 


9.60 


9.98 


10.05 


10.13 


Oxide of iron. 


1.36 


5.08 


1.93 


0.82 


Oxide of manganese. 


1.25 


9 


? 


? 


Phosphoric acid. 


49.32 


46.26 


40.63 


47.29 


Sulphuric acid. 


0.17 




0.26 


1.46 


Silica, 




3.07 


21.99 


0.17 



101.35 93.92 98.92 100 
There appears to be some mistake in the figures of this 
table, as will be seen on adding up the columns ; but still, for 
want of a more accurate one we must take this as it is, being 
sufficiently accurate for all practical purposes. 

ASHES OF THE F.ECES OF THE HORSE : ANALYSIS OF JACKSON. 

Phosphate of hme, 5.00 

Carbonate of do., 18.75 

Phosphate of magnesia, 36.25 

Silicic acid, 40.00 



100 

URINE OF THE HORSE I ANALYSIS OF VAUQUELIN. 



Carbonate of Hme, 


1.1 


Carbonate of soda. 


.9 


Hippurate of soda. 


2.4 


Muriate of potash, 


.9 


Urea, 


.7 


Water, 


44.0 



10* . 60.0 



220 SCIENTIFIC AGRICULTURB. 



ASHES OF THE F^CES OF THE COW : 


ANALYSIS OF HAIDLEN. 


Phosphate of Hme, 


10.9 


Phos. magnesia, 


10.0 


Phos. h'on, 


8.5 


Carbonate of potash, 


8.5 


Sulphate of hme, 


3.1 


SiHcic acid, 


63.7 


Loss, 


2.3 



107.0 

URINE OF THE COW : ANALYSIS OP BRANDE. 

Muriate of potash and ammonia, 1.5 

Sulphate of potash, 0.6 

Carbonate of potash, 0.4 

Phosphate of hme, 0.3 

Urea, 0.4 

Water, 96.8 



lOO 

ASHES OF HUMAN F^CES : ANALYSIS OF BERZELIUS. 

Sulphate of lime and phosphate of hme and magnesia, 67 

Sulphate of soda and potash and phos. of soda, 5 

Carbonate of soda, 6 

Sihcic acid, 11 

Carbon and loss, 12 

100 

HUMAN urine: ANALYSIS OF BERZELIUS. 

Urea, 30.10 
Lactic acid( ?) lactate of ammonia( ?) extractive 

animal matter, 17.14 

Uric acid, 1.00 

Mucus, 0.32 

Sulphate of potash, 37.01 

Sulphate of soda, ' 3.16 

Phosphate of soda, , 2.94 



SCIENTIFIC AGRICULTURE. 227 

HUMAN URINE — ContintiecL 

Muriate of soda, 4.45 

Phosphate of ammonia, 1.65 

Phosphate of magnesia and lime, 1.00 

Muriate of ammonia, . 1.50 

Silicic acid, 0.03 

Water, 953.00 



1000 
guano: analysis op volkel. 

Muriate of ammonia, 4.2 

Oxalate, do 10.6 

Ufate, ^^0 9.0 

Phosphate dfo 6.0 

Sulphate of potash, 6.5 

Sulphate of soda, 8.8 

Phosphate of ammonia and lime, 2.6 

Phosphate of lime, 7.0 

Oxalate of do. 14.3 

Residue soluble in uric acid, 4.7 
Loss, (water, ammonia and organized matter,) 32.3 

100 

BONES OP THE OX I ANALYSIS OF BERZELIUS. 

Animal matter, (gelatine,) 33.30 

Soda with common salt, 1.20 

Carbonate of hme, 11.30 

Phosphate of do. 61.04 

Fluoride of calcium, ( T) 2.00 

Phosphate of magnesia, 1.16 

100 
COAL 6oot: analysis of braconnot. 
Ulmio acid, 302.0 

A j^ddish brown substance containing nitrogen^ 

and yielding ammonia when heated, 200.0 



228 SCIENTIFIC AGRICULTURE. 

COAL SOOT — Continued. 

Asboline, 6.0 

Carbonate of lime with a trace of magnesia, 146.6 

Acetate of lime, 56.5 

Sulphate of lime, 60.0 

Acetate of magnesia, 5.3 

Phosphate of Hme, with a trace of iron, 50 

Chloride of potassium, 3.6 

Acetate of potash, 41.6 

Acetate of ammonia, ^ 2.0 

Silica, 9.5 

Charcoal powder, 38.5 

Water, 125.0 

100 

WOOL, HAIR, horn: ANALYSIS OF JOHNSTON. 

Wool. Hair. Horn. 

Carbon, 50.65 51.53 51.99 

Hydrogen, 7.03 6.69 6.72 

Nitrogen, lV.7l 17.94 17.28 

Oxygen and sulphur, 24.61 23.84 24.01 

100 100 1000 

DRY OX BLOOD AND MUSCULAR FLESH! ANALYSIS OF PLAY- 
FAIR AND BOECKMAN. 

Dry Flesh. Dry Blood. 

Carbon, 51.83 51.96 

Hydrogen, 7.57 7.25 

Nitrogen, 15.01 15.07 

Oxygen, 21.37 21.30 

Ashes, 4.23 4.42 

100 100 

URINE OF THE HOG I ANALYSIS OF VON BIBRA. 

Extractive matter soluble in water, 1.42 

« « « in alcohol, 3.85 

Salts soluable in water, 9.09 



SCIENTIFIC AGRICULTURE. 229 



URINE OF THE HOG Contin 


■ued. 


Salts insoluble in water, 


0.88 


Urea, 


2.75 


Mucus, 


0.05 


Water, 


981.96 



1000 

URINE OF THE GOAT : ANALYSIS OF VON BIBRA. 

Extractive matter soluble in water, 1.00 

« in alcohol, 4.54 

Salts soluble in water, 8.50 

" insoluble in do. 0.80 

Ui;ea, 3.78 

Hippuric acid, 1.25 

Mucus, 0.06 

Water, 980.07 



1000 

Remark. — We have, all through the course of this treatise, 
adhered to the principle that nature preserves a uniformity in 
the execution of all her laws, and that she does nothing by 
accident. And whenever we find an apparent exception to 
this principle, it is evident that our knowledge is deficient or 
our conclusions erroneous. 

Hence, although plants may be made to maintain a transi- 
tory and sickly existence without all the usual elements, and 
to absorb both by their leaves and roots, substances unne- 
cessary and pernicious to their growth, still from the uniformity 
of the elements and their proportions, as shown by analysis 
of the plants and the soils in which they thrive best, we 
are compelled to conclude, that each and all of these ele- 
ments, are indispensible to their healthy growth and maturity. 
And whoever lyractically disregards this principle, and hangs 
his hopes of success on some contingent cireumstance, must 
correct his error at his own cost. 



CHAPTER VIII. 



ANALYSIS OF SOILS. 



The agriculturist may, by long experience and close obser- 
vation of the character and productions of his lands, become 
acquainted with their general character and fertility, — and 
also what plants are best adapted to them. But it is desirable 
that a more accurate knowledge of the elementary constitution 
and the relative proportions of those elements which constitute 
the food of plants, should be attained. 

The only direct and certain means of arriving at this result 
is chemical analysis. Without this process, it could only be 
known by a trial of various crops upon different soils, whether 
they were adapted to them or not : and, in order to determine 
the value of soils in this way, several crops and much labor 
might be lost in unsuccessful experiments. 

Analysis of plants shows with absolute certainty what sub- 
stances they have drawn from the soil and atmosphere 'for 
food ; these substances vary in different plants, both in their 
nature and proportions: the same is also true in relation to 
the elementaiy composition of soils. No two plants and no 
two soils have precisely the same chemical composition. The 
absence of a single element in a soil may render it totally bar- 
ren for a particular crop, while it may produce some others in 
great abundance. 

A chemical difference in two soils, which might appear 



SCIENTIFIC AGRICULTURE. 231 

insignificant, would, by experiment, be found to alter entirely 
their relative ao-ricultural value. 

By referring to tables of the analysis of plants, and then 
analyzing the soil, we can see at once what plant the soil is 
adapted to produce. A soil containing all the organic and 
inorganic elements of a particular plant, may be supposed 
capable of producing the plant : but a soil deficient in one or 
more of these elements cannot be expected to yield a crop. 
A soil containing very Httle silica could not yield grass, but 
might still contain enough for a crop of turneps. 

An exact analysis of the quality of a soil, with the quantity 
of each element, requires the skill of a practical chemist, and 
the apparatus of a laboratory : but the most important quahties 
of a soil may be determined by a few plain and simple experi- 
ments, wliich are easily made by any one, whether acquainted 
with chemistry or not. 

The soil is made up, as before said, of various proportions of 
animal, vegetable, mineral, earthy and gaseous matters. As a 
general rule, the earthy part of the soil is estimated at from 
90 to 96 per cent. The salts of these earthy matters are in 
small quantities. The amount of vegetable matter varies 
greatly in different soils ; in some, as in peat and muck soils, it 
constitutes from one-half to three-fourths of their entire 
weight ; while in sand and clay soils, it amounts to only fi'om 
one to five per cent. The principal bulk of all soils, (except 
peat, humus and muck soils,) is sand, clay and hme; and on 
the proportions of these, their pecuhar properties, both chemi- 
cal and physical, depend. The fertility of a soil is not depen- 
dent upon any one of these, but upon the proportions and 
state of mechanical division of all the other necessary elements. 
The mixture of sand and hme with the other elements, (except 
the alumina,) is usually entirely mechanical: in the various 
kinds of clay, the silex and alumina are often chemically com- 
bined, constituting a siHcate of alumina. 



232 SCIENTIFIC AGRICULTURE. 

The first process in the analysis of a soil is to weigh a given 
quantity with apothecaries' scales : it should then be spread 
out on a piece of clean paper and subjected to a heat not suffi- 
ciently high to burn the vegetable matters which it contains, 
until thoroughly dried: after drying, the soil should be again 
accurately weighed, and the second weight subtracted from 
the first, when the remainder will show the amount of water 
lost. 

To find the amount of organic matter which it contains, put 
the dried soil into an earthen crucible and heat it over a fire 
to redness, till the organic matter is burned out and the ash 
only remains ; after cooling, it should be again weighed, — ^the 
loss by burning shows the amount of organic matter it con- 
tained, allowing a trifle for the charcoal which remains vritli 
the earthy pari If a black soil loses nothing by burning, it 
probably derives its color from black oxide of iron or graphite. 

To detect humie acid, boil a small quantity of peat or muck 
in a solution of carbonate of soda, until it attains a brown 
color, then add muriatic acid till the solution has a distinctly 
sour taste, when broAvn flocks of humic acid will fall to the 
bottom. 

Ulmic acid may be obtained from the same soil, after the 
humic acid is separated, by digesting it over a gentle heat in a 
solution of caustic ammonia, and then adding muriatic acid as 
before ; — ^brown flocks are precipitated, which are ulmic acid. 

To detect crenic and apocrenic acids, digest a quantity of 
soil in hot water until organic matter* is dissolved out sufficient 
to give the water a yellow color. When this solution is evapo- 
rated to dryness, there remains a brown residue, which con- 
tains the soluble saline matters of the soil, some extractive 
matter, humic and ulmic acids, and the crenic and apocrenic 
acids: these four acids ai-e all in combination ^nth. alumina 
and other bases. When this residue is dried at 220° F., the 
compounds of the humic and ulmic acids become insoluble, 



SCIENTIFIC AGRICtJLTURE. 233 

while tlie compounds of the crenic and apocrenic acids remain 
soluble, and may be separated by washing in water. — [Johnston. 

To detect the presence of lime, take 100 grains of a soil and 
mix well with half a pint of cold water, and then add half an 
ounce of muriatic acid, stirring the mixture frequently : let it 
stand a few hours to settle, then pour off the water and fill the 
vessel with water to wash out the excess of acid ; when the 
water is clear, pour it off, dry the soil and weigh it ; — the loss 
from the first weight will show the quantity of lime sufficiently 
near for all practical purposes. — [Gaylord. 

To determine the amount of sand, take a given quantity of 
soil and boil it in water till it is thoroughly incorporated with 
it, then pour the whole into a glass vessel and leave it till the 
sand subsides : the clay remains in a state of mixture with the 
water, which should be poured off and the sand dried and 
weighed. If the sand contains lime, it may be separated by 
muriatic acid as above directed. 

The amount of clay may be very nearly ascertained by 
evaporating the water which was poured off of the sand, — 
the residue Avill be mostly clay. 

To detect the presence of oxide of iron, mix a quantity of 
soil with water, pour on muriatic acid and stir the mixture; 
let it stand a few hours and dip a piece of oak bark into the 
solution, — if the bark is colored brown or black, iron is present. 

" To detect the presence of other salts, boil a portion of soil 
in water, pour off the water and evaporate it, when the salts 
may be obtained in crystals. 

" If the salt is a nitrate, it has a cool pungent taste, and 
ignites when thrown on coals of fire. 

" If it be common salt, (muriate of soda,) it burns with a 
crackling noise, and is also known by its taste. 

" Sulphate of soda puffs up by heat, gives off a watery vtipor 
and leaves a diy white mass." 

These directions are sufficient to enable any one to make a 



234 SCIENTIFIC AGRICULTURE. 

rough analysis of a soil, which, although not strictly correct, 
may be of much service in determining the general character 
of a farm, when a rigid and exact analysis cannot be obtained. 
We give below two tables, — one showing the composition of a 
barren, and the other of a fertile soil. Taking the mineral 
constituents of plants as a basis on which to predicate our rea- 
soning in relation to the productive value of soils, we see at 
once, that one of these tables shows a soil rich in all the 
elements of fertility, while the other exhibits one almost irre- 
deemably barren. 

ANALYSIS OF A NEW SOIL ON THE BANKS OF THE OHIO RIVER, 
POSSESSING GREAT FERTILITY. 

Quartz sand and siUcates, 87.143 

Alumina, 5.666 

Oxides of iron, 2.220 

Oxides of manganese, 0.360 

Lime, 0.564 

Magnesia, .0.312 

Potash and soda, 0.145 

Phosphoric acid, 0.060 

Sulphuric acid, 0.027 

Chlorine in common salt, 0.026 

Humic acid, 1.304 

Insoluble, humus, 1.072 

Or<xanic matters containing: nitroe'cn, 1.011 

CD O O ' 

Carbonic acid united to the hme, 0.080 

ANALYSIS OF A SANDY SOIL, UNFIT FOR CULTIVATION. 

Silica and quartz sand, 96.000 

Alumina, 0.500 

Oxides of iron, 2.000 

Oxides of manganese, trace. 

Lime, 0.001 

Magnesia, " trace. 



trace. 


0.200 


1.299 





SCIENTIFIC AGRICULTURE. 235 

ANALYSIS — Continued. 

Potash, trace. 

Soda, do. 

Phosphoric acid, do. 

Sulphuric acid, do. 

Carbonic acid. 

Chlorine, 

Humic acid, 

Insoluble humus. 

Water, 

100 

Chemically. considered, a soil must contain all the inorganic 
elements which plants require, and none that are injurious to 
them. If the addition of a certain manure render a soil more 
fertile, it is evident that the soil was deficient in one or more 
of those substances which it furnished. If the addition of a 
given manure or salt to a defective soil, fail to improve its fer- 
tility, it is because enough of this substance is already present, 
or because some other substance is wanting to render this 
apphcation available. A soil may sometimes show more or 
less fertility for certain crops than analysis would indicate, on 
account of some mechanical and physical conditions: in this 
way the supply of certain elements may be cut ofi^ although 
they are present in the soil : the deficiency of others may also 
be partially compensated by the same causes. 



CHAPTER IX. 



CHEMISTRY OF THE DAIRY; OR THE ART OF MAKING BUTTER 

AND CHEESE. 

Products of Land. 

All agricultural products may be comprised in three classes, 
— viz. 1. Those which are directly taken from the soil, — such 
as roots, grains, hay, fruit, &c. 2. Those which are indirectly 
derived from the soil, in the form of beef, pork, poultry, wool, 
eggs, (fee. : these have been manufactured from the immediate 
products of the soil, by the chemical and vital processes in the 
bodies of animals. 3. Those products, such as butter, cheese 
and milk, which are the result of still further process of manu- 
facture by chemical means combined with mechanical skill. 

The first class of products are briefly described and some 
analytical tables given in other parts of this book. But a full 
and detailed description of their elementary substances, and 
their absolute and relative value as means of producing the 
second class, that is, as food for raising stock and fattening diflfe- 
rent animals, — would require a treatise on organic chemistry 
and physiology far exceeding our plan. 

We shall, therefore, briefly indicate in relation to these two 
classes, the conditions which influence their quantity and quality 
as food, both for men and animals. 

Climate has an important influence in varjdng both these 
conditions. 



SCIENTIFIC AGRICULTURE. 237 

Warm climates produce richer and more abundant and 
luxuriant vegetation than cold ones. Nearly all grains, fruits, 
spices, gums and sugars, are the products of temperate and warm 
countries; wliile the products of cold countries are stinted, 
scanty, and inferior in the elements which are best fitted for 
food. Soils, according to then- character, vary the value of 
their productions: a rich soil, well adapted to the crop pro- 
duced, yields richer food and in greater quantity than a poor 
soil. Warm and dry soils yield sweeter roots and fruits, — and 
grains which make more flour and less bran and straw, than 
cold and wet ones. The soil must be, in all respects, adapted 
to the crop, in order to yield the maximum quantity of the 
best produce. The quality and variety of the seed is also 
important ; defective seed is apt to produce inferior crops ; one 
variety of grain or grass may succeed where another would be 
a failure : the quantity of seed sown is to be considered also. 
The method of culture, as relating to tillage, rotation, manuring, 
time of sowing and harvesting, are all circumstances necessary 
to be considered. 

Milk — its Properties. 

Milk is an oily fluid of an opake white color, tinged often 
with pale blue or yellow hues, and having a specific gravity 
three per cent, greater than water, — or in the proportion of 103 
to 100. Fresh milk is shghtly alkahne; it is, however, some- 
times sour immediately after milking on account of remaining 
in the udder too long. If milk be agitated it becomes warmer 
and turns sour, — and the fat separates from the other matters. 
If acid be added to milk, it separates into a solid and a fluid 
part, viz. the curd and the whey : sour milk and rennet produce 
the same effect, — this occurs also spontaneously where milk is 
allowed to stand and sour. When sour milk is warmed it 
ferments and yields intoxicating spirit: sour milk, when 
exposed to the air, p-trifies and is unwholesome as food. The 



238 SCIENTIFIC AGRICULTURE. 

milk of all animals differs : cow's milk is best for butter. The 
composition of milk is given in the following table : — 
Casein, 1.52 

Butter, 3.55 

Milk sugar, 6.50 

Saline matters, 0.45 

Water, 87.98 

Of these elements, sugar and butter contain no nitrogen, 
while casein contains a considerable quantity. 

Causes affecting the Quality of Milk. 

The first milk after the birth of the young is called the colo- 
strum; it is thicker and more yellow, and contains much more 
casein than other milk, — it coagulates by heat. This quahty 
of milk continues from ten to fifteen days after the birth of the 
calf, when it assumes its natural properties, and is fit for use. 

The best milk is yielded by cows that have had three or 
four calves : most cows continue to give good milk in conside- 
rable quantity until the age of ten or twelve years, when the 
quantity diminishes, the quality deteriorates, and the cow is 
disposed to the accumulation of fat: they are then most profi- 
table to fatten for beef Cool weather favors the formation of 
cheese in the milk, while warm weather favors the production 
of butter. Milk is yielded in larger quantity and of better 
flavor in spring than at any other season of the year. This 
depends somewhat on the quahty of the cow's feed, — the fresh, 
sweet herbage of spring, doubtless gives milk superior to that 
made from any other /ood 

Perfect health of the cow is indispensible to the production 
of good milk. During the pregnancy of the cow, and also 
when she is disposed to the accumulation of fat, the milk yields 
less cream. Cows that are milked two or three times a day, 
}aeld more milk than those milked but once a day ; but this 
milk is less rich, and yields far less butter, than that from cows 
milked but once a day. The best system for milking is twice 



SCIENTIFIC AGRICULTURE. 239 

in twenty-four liours, at nearly equal intervals. The last milk, 
or " strippings," is richest in cream, often containing from eight 
to sixteen times as much as the first. This is accounted for by 
the tendency of the cream to rise to the top of the milk, even 
in the udder of the cow. 

The quahty of the milk is aflfected by worrying, chasing, 
"dogging," change of pasture, habits, and companions, — and 
also by depriving them too early of the calf The quality 
depends much also on the breed and size of the cow, — but this 
question we have not space to discuss. Food, as before said, 
aflfects the quality of the milk ; leeks, onions and turnips impart 
their taste to it, — madder gives it a reddish, and saffron a 
yellowish, tinge: one kind of pasture produces milk which 
yields more butter and another more cheese. Oily food, such 
as house slops, corn and oil cake, give milk which yields more 
butter, while leguminous seeds, such as peas and beans, pro- 
duce more cheese. 

Causes affecting the Quantity of Milk. 

With those dairymen who depend mainly on the sale of the 
milk for profits, the quantity is of the first importance. This 
depends very much on the breed, size, age and form of the 
coAv. All succulent food, such as juicy grass, steamed food, 
brewers' grains, distillers' slops, turnips, beets, carrots, potatoes, 
pumpkins, apples, and a full supply of good water, — tend to 
increase greatly the quantity of milk, over that yielded by dry 
food. Such milk, however, is less rich in butter, cheese and 
sugar, because it contains a larger proportion of water. 

About two months after the birth of the calf, the milk 
gradually diminishes in quantity until the end of about the 
tenth month, w^hen the cow becomes nearly or quite dry. 
Some cows milk longer than ten months, but these are 
exceptions to the rule : milking, or the secretion of milk, may 
also be kept up by peculiar feeding and other management for 



240 SCIENTIFIC AGRICULTURE. 

two or tliree years without any cessation, — but the milk is 
poor and watery, after the time the secretion should cease. 

Separation of the Mements of Milk 

The immediate cause of milk becoming sour, is the conversion 
of sugar into lactic acid ; this is induced by the action of casein. 
This change may be prevented and milk kept sweet for a long 
time by keeping it at a low temperature ; but even then it 
gradually becomes sour after some time. If milk be boiled 
and kept in a cool place, it will remain sweet for half a year. 
At 65° to 70° it sours rapidly; if then it be heated to boiling 
it curdles. Sourness may be removed or prevented by salaera- 
tus, soda or magnesia. They should be added until the milk, 
when dropped into hot water, no longer gives a curd. Milk 
may be preserved any length of time by evaporating it to dry- 
ness, and keeping the mass dry and cool. 

The cream contains the fat or butter which is held in sus- 
pension by the watery part of the milk ; the cream will be all 
separated from a given quantity of milk sooner, if placed in 
shallow vessels. More cream will arise also in a given time in 
warm than in cold weather, as shown by the following table : — 

At 34° F. milk requires two or three weeks to throw up all 
its cream. 

At 50° it creams perfectly in 36 hours. 

At 55° " " " 24 « 

At 68° " " " 20 « 

At 77° " " "12 " 

Cream rises more slowly in cold weather, because the fat 
becomes partiall}'- solidified by cold. Cream is composed of 
fat, casein and milk sugar, in the proportions shown beJow 
from an analysis by Berzelius : — 

Butter, 4.5 per cent. 

Cheesy matter, 3.5 " 






Whey, 92.0 

\ 100 




SCIENTIFIC AGRICULTURE. 241 

This specimen of cream must have been very poor in butter 
and cheese. A wine gallon of cream weighing* 8^ pounds yields 
nearly two pounds of butter, — that is, nearly one-fourth its 
weight of butter. Cream cheese is rich in butter but soon 
becomes rancid. When cream is heated or agitated, the oil 
separates and rises to the top in the form of butter. Swee4; 
cream requires churning much longer and makes no better 
butter than that wdiich is slightly sour : it should therefore be 
at least one day old, and is better to stand several days until 
a small part of the sugar is changed to lactic acid. In all 
cases, sweet cream soui-s during churning before butter forms. 
The w^kole mJlk wdien churned, gives more butter than the 
cream alone would do: warm w^ater added to cream durino- 

o 

churning, facilitates souring, and consequently hastens the for- 
mation of butter. Buttermilk is always slightly sour after the 
butter is separated from it; — it still contains the casein or 
cheese of the milk. Fresh butter is mainly oil containing 
variable quantities of casein, water and sugar of milk : about 
five-sixths of butter is pure fat, and one-sixth, the other ingre- 
dients. These proportions are not constant, but depend upon 
the quality of the milk and the mode of making the butter. 

Butter also contains minute qantities of some coloring mattera 
and aromatic flavor derived from the food of the cow. Butter 
may be separated from the other matters and obtained pure, 
by heating it to 140° to 180° R, and then agitating it with 
water at the same temperature, then pouring off the butter 
and repeating the process until it remains a transparent oil, 
which hardens into a colorless mass wdien cold. This keeps 
sweet much longer than other butter, for the reason that the 
other elements tend to decompose and produce rancidity. 

The average amount of butter yielded by one cow the year 
through, will hardly exceed half a pound a day. Cows ordi- 
narily average from 100 to 200 pounds of butter during a 
year. Butter made in spring, particularly in May, is much 

n 



242 SCIENTIFIC AGRICULTURE. 

more pleasant in flavor tlian that made at any other season of 
the year: of the varieties of food spurry is said to produce 
milk which gives the finest flavored butter : dry food produces 
the hardest butter. Fall butter is considered best for keeping 
through the winter ; winter butter is lio-hter colored and less 
rich. The first cream makes the best butter. When churning 
is done too quickly, the butter is more soft and pale, and less 
rich : it is also injured by churning after the complete separa- 
tion of the milk from it. 

Cream should be at a temperature of 53° to 58° F. when 
put into the churn: whole milk should be at 65° F., — it always 
rises from 4° to 10° by churning. Whole milk yields better 
butter at all seasons than cream alone. When butter is long 
in separating, the addition of a Httle vinegar or brandy will 
hasten the process. 

Pure oil of butter contains the following elements : — 
Margarine, 68 per cent. 

Butter oil, 80 

Butyric, Caproic and Capric acids, 2 " 



100 
These elements vary somewhat with the season of the year 

and other circumstances. The capric and caproic acids are 
formed by fermentation caused by the contact of air, and give 
the unpleasant flavor to rancid butter. There are several 
causes which produce rancidity in butter: the contact of air 
with the surface is a common cause, — impure salt, or a defi- 
cient quantity of salt, is another cause, — the presence of butter- 
milk and casein is a common cause, — washing with water 
which is impure or too strongly impregnated ^vith lime,— butter 
which is allowed to stand long after churning, before being- 
worked and salte'(i, soon becomes strong. Immediately after 
churning, butter ought to be washed in cold spring water, 
worked until the buttermilk is all out, and then salted with 
the best fine salt, in the proportion of one part of salt to twenty 



SCIENTIFIC AGRICULTURE. 243 

four of butter, — or one and a half ounces to one pound of 
butter. A mixture of salt, white sugar and saltpetre is said to 
impart a fine flavor and prevent rancidity. Butter for packing 
should then be put into a cleiin cool firldn or stone pot with 
a layer of salt at the bottom ; it should be packed perfectly 
solid so that no air shall be left in the butter or between it and 
the sides of the vessel ; when the vessel is full, another layer 
of salt or strong brine should be put in, and the vessel closed 
air-tight and put in a cool place ; in this way butter will keep 
fresh for months, and perhaps for years. Stone vessels are 
better to pack butter in than wooden ones. 

• Curdling of the Milk. 

This change has been before partially explained, but it is 
necessary to advert to it here in connection with the manufac- 
ture of cheese. The transfoimation of milk suo-ar to lactic 

o 

acid, is the cause of the spontaneous curdhng of milk. In the 
process of making cheese, the milk is not left to curdle of 
itself, but is induced more speedily by the action of some other 
substance, as acid or rennet 

Various acids are used in some countries for this purpose, 
as, lemon juice, vinegar, tartaric and muriatic acids. The 
explanation of the action of acid in curdling milk, is as follows , 
The casein of the milk is combined, in its natural state, with a 
small quantity of soda, which renders it soluble in the water 
of the milk; now when an acid is added, the soda having a 
stronger affinity for the acid than for the casein, leaves the' 
latter and unites with the acid, while the casein, deprived of the 
soda, is no longer soluble in water, but solidifies and forms the' 
curd, which floats free in the whey or watery part of the milkJ 
When milk sours spontaneously, the first step in the process' 
is the change of milk sugar to lactic acid, — next the acid 
unites with the soda, forming lactate of soda; and lastly, the 
curd and whey separate. 

Heat hastens the curdhng by causing the soda and acid to 



244 SCIENTIFIC AGRICtTLTURB. 

combine more rapidly, and solidify in tlie curd more perfectly. 
Sour milk will induce tlie chemical changes of curdling just 
as perfectly but more slowly. 

Mennet is generally used in this country for this purpose. 
It is prepared from the stomach and intestines of the sucking- 
calf, the young lamb, kid or pig: the bladder of the pig is 
also used in some dairies. The part designed for use is washed 
and salted, then dried and laid aside for use. There are seve- 
ral ways of preparing the rennet. Some leave the curdled 
milk of the stomach in it, and prepare and use the whole 
together : this is useless and less cleanly. The best w^ay is to 
wash the stomach well, then pickle in strong brine and dry it 
for use : it improves b}'' age, and is considered best when ten 
or twelve months old; new rennet is thought to cause the 
cheese to swell and become porous. A piece of the dried 
membrane the size of a half dollar is said to be sufficient for 
sixty pounds of cheese. It is soaked in warm salted water or 
whey over night, — it is customary in some dairies to steep 
with it some aromatic substance, as sage, dog-rose, lemon peel, 
&c., — and also some coloring principle, as annatto, saffron or 
carrots. The rennet is then added to the milk, which is heated 
from 90° to 95° F., and stirred well together. The quantity 
of prepared rennet varies from a table-spoonful to half a pint, 
according to its strength, to thirty or forty gallons of milk. 
The process of curdling occupies from fifteen minutes to an 
hour and a half, depending on the quality and quantity of the 
rennet and the temperature of the milk. 

The action of rennet does not depend on the g*astric juice of 
the stomach, but on the membrane itself. By contact with air 
it becomes partially decomposed; the process of putrefactive 
fermentation has just commenced, and this slight change in the 
membrane is just sufficient to cause the change of the milk 
sugar to lactic acid, which completes the operation as before 
stated. When the membrane or stomach has undergone con- 



SCIENTIFIC AGRICULTURE. 245 

siderable change, it gives a strong tainted taste to the cheese. 
Any substance that will cause sugar to change to lactic acid, 
"will curdle milk : rennet is often prepared in whey instead of 
water ; and this is probably preferable. Rennet is also prefe- 
rable, as experience has proven, to any other substance for 
making cheese. 

Qualities of Cheese. 
All cheeses consist mainly of the curd of milk containing a 
portion of the oil and sugar. The richness of a cheese depends 
much on the amount of butter which the milk contains ; poor 
watery milk must necessarily yield a poor cheese ; the milk im- 
parts to the cheese whatever taste or other pecuharity it receives 
from the food of the cow. The milk of different animals yields 
various qualities as well as different quantities of cheese. The 
whole or uncreamed milk gives better cheese than skimmed 
milk ; a large part of the butter is removed with the cream ; 
hence the cheese is so much the less rich, and is more tough 
and sohd, and more hable to mould. Buttermilk cheese is made 
from the milk deprived of its butter by churning : it is mainly 
casein, and is pleasant flavored when fresh, but of poor quality. 
The whey always contains a considerable quantity of both butter 
and casein, and yields a second cheese which is of good quality. 
Cheese of good flavor is made of boiled potatoes and sour mUk. 
All qualities of cheese may be made of the same milk ; but we 
have not space to describe the various processes and conditions 
by which it is done. The curd is generally washed in hot 
water, which although it deprives it of some poi'tion of its 
butter, still renders it more solid and makes it keep better. 
Too much rennet makes the cheese tough and imparts to it a 
strong taste. The butter washed from the curd rises when 
the water is cold, and is settled and worked in the same way as 
churned butter. The curd should be completely separated 
from the whey or it will soon ferment and become strong : the 
salt used in the curd should be perfectly clean and pure '; — 



246 SCIENTIFIC AGRICULTURE. 



I 



cream and yolk of eggs is sometimes added to the curd to 
improve its riclmess. 

The size and mode of curing cheese have much influence in 
determining its qualit}^ : during ripening, cheese should be kept 
cool, frequently turned, cleaned and rubbed with salt butter. 
The ammoniacal cheese of France, is made from the unpressed 
curd; this is placed in a room warmed to 60° or '70° F., until : 
putrefactive fermentation has advanced considerably, and the 
cheese emits a strong ammoniacal odor: this cheese, like all 
putrefied animal matters, is unwholesome and unfit for food. 
A new flavor may be imparted to cheese by innoculation with 
some other cheese or some aromatic substance : this is done 
by scooping out a small canity in the centre, and introducing 
the flavor, and then closing the cavity. This penetrates the ^ 
whole cheese, and imparts its peculiar taste. B' 

The question of the profit of the different products of the 
dairy cannot be discussed here. Prof. Johnston thinks that in 
the countiy, where the milk cannot be sold, the manufacture 
of butter and skim-milk cheese, yields the largest profits of any 
method. The tables below show the average amount of the 
different dairy products, from 100 pounds of milk: — 

100 lbs. average milk gives 

6 to 7 lbs. skimmed milk cheese, 
9 to 10 lbs. entire milk cheese. 

100 lbs. average milk gives 

6 lbs. skimmed milk cheese, 

3|- lbs. butter, 
14 lbs. buttermilk, 
1Q^ lbs. whey. 

These proportions vary according to circumstances. In Che- 
shire, Eng., one good cow's milk will yield one pound of cheese 
a day, on an average, tln-ough the year. Eight to ten pounds of 
milk usually yield one pound of cheese from the whole milk. 



SCIENTIFIC AGRICULTURE. 247 

]\lilk and buttermilk may undergo vinous fermentation and 
yield alcoholic spirit : this spirit is produced and used for its 
intoxicating effects among the Tartars, Arabs, and in some 
parts of Ireland and Scotland. In this process the sugar of 
milk is changed to alcohol, which, by being kept in a warm 
place, disappears and leaves vinegar in its place: vinegar is 
made to some extent in this way in Italy. 

The table below shows, according to an analysis by 
Haidlen, the proportions of the solid constituents of milk : the 
milk was boiled down to a dry mass and this burned to ashes : 
100 lbs. yielded— 

• Phosphate of Lime, 3,44 

Phos. Magnesia, 0.64 

Phos. of per-oxide of Iron, 0.07 

Chloride of Potassium, 1.83 

Chloride of Sodium, 0.34 

Free Soda, 0.45 

This analysis approximates the truth sufficiently near for all 
practical objects : different varieties of milk give a slight varia- 
tion in the proportions of the elements. 

As an article of diet, milk is the tj^pe or pattern of all food ; 
particularly for the young of all mammiferous animals. It con- 
tains all the elements necessary to the support of life in all of 
this class, both the young and the old. The casein is almost 
identical with lean flesh, and serves to supply many of the ele- 
ments required for its growth. The butter is partly consumed 
in the capillary system as fuel for animal heat, and the residue 
goes to the accumulation of fat. The milk sugar is mainly an 
element of fuel for animal heat. The salts are taken up 
by the blood and are found in all the secretions. The earthy 
matters, such as phosphate of Hrae, go to the formation of the 
sohd portion of the bones. It is evident, from the composition 
of milk, that the diet of the cow must be of a compound or 
mixed nature ; no food that does not contain all the elements 



248 SCIENTIFIC AGRICULTURE. 

of milk, will enable a cow to furnish it; and no milk deficient 
in any element will long sustain life : milk deficient in phosphate 
of lime, produces, in the young animal, a soft and rickety state 
of the bones. The same is true of the food of plants. No 
plant can grow in a soil which does not contain all the elements 
of food which it requires for its growth. 



CHAPTER X. 



MECHANICAL PHILOSOPHY. 

Mechanical pliilosophy treats of tlie equilibrium and mo- 
tion of bodies: its great object of inquiry is, into the causes 
which produce or prevent motion, and the manner in which it 
takes place. " That part of mechanics which relates to the ac- 
tion of forces producing equihbrium or rest, in bodies, is called 
statics; that which relates to the action of forces producing 
motion is called dynamics.''^ 

The practical value of this branch of science consists in the 
application of a few simple mechanical powers, either singly or 
combined in some kind of machinery, in overcoming resistances 
and producing and applying motion to useful pm^poses. 

" Poivcr is the means by which a machine is moved and 
force attained ; thus we have hoi'se power, water power, steam 
power, &c. 

^'Force is the means by which bodies are set in motion, kept 
in motion, and when moving are brought to rest. The force 
of gunpowder sets a ball in motion and keeps it moving until 
the resisting force of the air, and the force of gTavity bring it 
to rest." 

A few simple instruments or machines variously combined, 

produce all the comphcated, powerful and beautiful pieces of 

macliinery which have ever been constructed. 

These few elementary powers are, the lever, the wheel and 

11* 



250 SCIENTIFIC AGRICULTURE. 

axle, tlie pulley, the inclined plane, the wedge and the screw. 

The lever is a straight bar placed upon a supporting point 
called a fulcrum, with the resistance which is to be overcome, 
at one end, and the power applied, at the other. 

The wheel and axle is somewhat more complex than the | 
lever; it consists of two concentric wheels, one of Avhich is ! 
larger than the other, and both revolving on a common axis. i 
This power acts hke a succession of levers, and is therefore a M I 
modification of the lever. - '■ 

The pulley consists of a flat disc, "vvith a groove on the edge, 
through which a rope passes, and a hole in its centre, through 
which a fixed axis passes, on which it revolves : when several 
pulleys are combined, they constitute a system of pulleys, or a 
compound pulley. The power of a system of pulleys increases 
in proportion to the number of pulleys employed. 

The inclined plane, as its name impHes, consists merely of a 
plane surface, with one of its ends higher than the other, so 
that the plane forms an angle with the horizon. 

The wedge may be considered as two inclined planes with 
their bases placed together, and their apices forming an acute 
point. The power of the wedge depends upon its relative 
length compared with the width of its base, — or upon the 
degree of taper from the base to the point. 

The screw is the sixth mechanical power, and may be con- 
sidered a continuous spiral wedge, or a modification of the 
inclined plane. The power of the screw depends upon the 
relation between its circumference and the distance between 
its threads. 

OBJECTS AND ADVANTAGES OF MACHINERY. 

No actual power is ever generated by machinery ; force and 
velocity may be gained, but they are always gained at the 
expense of the motive power apphed to work the machine: 
the power and force must always be in exact proportion to 
each other, so that, if one is increased, the other is diminished 



MECHANICAL PHILOSOPHY. 251 

in the same proportion. Great velocity in a macliine, or in anj 
of its parts, is incompatible with great power also ; for whatever 
is gained in speed is lost in strength, — that is, it is gained at 
the expense of power or force. 

It is not expected to gain power, force and velocity at the 
same time by the use of any mechanical contrivance whatever, 
— but, by taking a philosophical advantage of the few simple 
mechanical powers, to obtain one or the other of them, 
according to the labor to be performed. 

The advantages of macliinery are numerous. 

1. By the aid of machinery we can apply force to much 
better j)urpose than by our unassisted hands. 

2. A man can perform a w^ork by its aid, to which he would 
be wholly incompetent without it. 

3. It often enables men to exert their whole force, Avhere 
without it they could exert only a small part of it. 

4. It enables us to employ animals in the execution of many 
kinds of work which must otherwise be performed by man 
himself. 

5. It enables us to employ several inanimate motive powers, 
such as water, steam, wind, heat, electricity, &c. 

6. Many manufacturing operations are performed with much 
greater facility and exactness than they could be by hand. 

7. Macliinery saves a considerable part of the materials used 
in the manufacture of many fabiics. 

ON REGULATING THE MOTION OF MACHINERY. 

The motion of machinery, to operate to the best advantao-e, 
should be perfectly regular and uniform. Variations of motion 
consist principally in variations of power, weight or resistances, 
and changes of velocity in different parts of the machine itself. 
The different instruments used to obviate these effects, and 
secure uniform motion, are called regulators. There can be 
little doubt that watei-, where it is abundant and available, 



252 SCIENTIFIC AGRICULTURE. 

furnishes the most economical motive power, and one which 
propels machinery with greater uniformity than any other 
which we possess. 

Among the instruments used for modifying and regulating 
motion are, the jiy wheel, governor, ratchet wheel, umversal 
joint, cranJc, eccentric wheel, arch head, pendulum, knee joini^ \ 
fusee, &c. ! 

Every part of a machine ought to be proportioned to the 
stress it is to bear, and the strength it requires, — and should > 
be no heavier than necessary; all parts should bear their 
relative proportion of the work and wear, so that when the 
machine fails, all parts shall be worn out. Every machine 
should consist of as few parts as possible ; because, when parts 
are multiplied, friction is increased in the same proportion, and 
the machine is more Hable to get out of repair. All mechanical 
obstacles and errors have a less ratio to the motion in great 
than in small machines ; the former, therefore, work with more 
uniformity and exactness, but are proportionally weaker and 
more Hable to be broken. f | 

Motion and rest are both equally accidental states of matter * 
bodies are no more disposed to lie at rest than to put them 
selves in motion : they maintain a state of rest so long as there 
is an equihbrium of all the forces acting upon them ; and when 
they assume a state of motion, it is because they are acted 
upon by some extrinsic force, which is stronger than the com- 
bined action of all those which tend to keep them at rest 
When once in motion, bodies would continue moving forever, 
if no force obstructed them to destroy the equilibrium between 
accidental resistances and the propelling force ; in other words, 
they would never come to rest, unless brought to rest by some 
power superior to that which set them moving. 

Motion may be absolute or relative: absolute motion is a 
change of place by a body, in relation to some fixed point : 



MECHANICAL PHILOSOPHY. 253 

relative motion is a change of place by a body in relation to 
some other body which is in absolute motion. 

Motion is also distinguished into that of progression, and 
that of rotatioii. 

Simple motion results from the action of a single force upon 
a body, while compound motion is produced by two or more 
forces acting in different directions. Motion, when once attained 
woidd be onward in a straight Hne unless changed or destroyed 
by some force secondary to the one by which it was produ- 
ced: a ball projected from a cannon, assumes a curved hne 
towards the earth, because acted upon by the attraction of 
gravitjn and this sufficiently strong to overpower the propel- 
ling force of the powder wliich gave it motion, and finally bring 
it to rest. 

OBSTRUCTIONS TO THE ACTION OF MACHINERY. 

Friction arises mostly from the elevations of one surface 
entering into the depressions of another ; but partly also from 
the mutual cohesion of the surfaces. 

Sliding friction is produced when pinions or axes revolve on 
their support. 

Rolling friction occurs when a round ball or wheel rolls 
alon2[ a surface. Friction is greater between two surfaces of 
wood where their fibres lie parallel than where they run across 
each other : it is also gTcater between two surfaces of the same 
metal than between those of different metals : tv/o surfaces of 
iron would produce more friction than one of copper and one 
of iron : cast steel is said to be an exception to this rule. 

The resistance of friction may be diminished by the nse of 
fine smooth and oily substances; the particles of w^hich fill up 
the cavities and lubricate the asperities of the surfaces. For 
this purpose oil is best adapted to metals, and tallow for wood. 

Extent of surface makes no difference, in a given body, in 
regard to the amount of friction developed. The sum of the 



254 SCIENTIFIC AGRICULTURE. 

friction of all parts, is the same for a greater or less surface, — 
other conditions being the same. Friction is increased between 
two bodies by their remaining some time in contact ; in some 
cases it does not attain the maximum in four or five days. In 
the contact of two metals, the friction attains its highest point 
in a few seconds : two pieces of wood attain their utmost fric- 
tion in one or two hours : when iron runs upon oak the friction 
will increase for four or five days. The friction of quiescence 
is greater than that of motion. 

Friction is less after motion becomes well established and 
rapid, than when it first commences. The whole efficacy of 
the screw depends upon the friction between the threads of 
the external and internal screw : the screw being an inclined 
plane, if there was no friction it would unscrew, or the inter- 
nal screw would descend by its own gravity when placed ver- 
tically. Query : What relation has the development of fric- 
tion to electricity ? 

The resistance of the atmosphere, which in some machines 
must be considerable, is another obstruction to the action of 
machinery. The weight or gravity of a machine itself, or of 
some of its parts, is sufficient in some cases to require a consi- 
derable part of its power to overcome it. 

Adhesion always exists conjointly with friction, and must be 
deducted from estimates of the amount of friction in all cases. 
Adhesion exists independently of pressure, and is in proportion 
to extent of surface. Oils and unguents, used to diminish 
friction, always increase adhesion in proportion as they increase 
the number of points of contact between the two surfaces. 

STRENGTH OF MATERIALS. 

It is important, in the construction of all pieces of archi- 
tecture and machinery, that the mechanic should know the 
strength of the materials which he is to employ in the work. 
By strength, we understand the power which a body has, by 



MECHANICAL PHILOSOPHY. 255 

the cohesive force of its particles, to resist fracture : stress is 
the power or tendency iu a body to produce fracture by its 
own weio-ht. 

o 

A joist eight inches wide and two inches tliick, is four times 
as strong w^hen laid on its edge as when laid on its side. 

"A trimigular beam is twice as strong when resting on its 
broad base as when restino- on its edge." 

" The strength of a column in the dh'ection of its length, is 
directly proportional to the area of its transverse section." 

" Half the length of a beam supported at both ends, will 
bear four times as great a pressure as the Avhole beam ; and a 
prop placed under the centre of a beam increases its strength 
in the same ratio." 

The strength of a beam increases from the centre towards 
the ends or points of support, and the stress increases from 
the ends towards the centre; hence, a beam to be equally 
strong at every point, should be eliptical, or the largest in the 
middle and taper regularly towards both ends. 

The strongest form in which a given quantity of matter can 
be disposed, is that of a hollow cylinder : this, however, is true 
only when the transverse sections of the cyHnder are perfectly 
circular. In this way nature economizes material, avoids too 
great weight, and at the same time augments strength. 

**A great column is in greater danger of being broken than 
a similar small one ; an insect can sustain a weight many times 
greater than itself, — whereas a much larger animal, as a horse, 
could scarcely carry another horse of his own size." 

It is not regarded as safe to load a stone structure with more 
than one-sixth the amount of pressure which it requires to 
crush it : iron may be loaded to one fourth that amount. In 
building bridges, &c., w^hich are to span considerable space 
without as much support as might be desirable, it is important 
to calculate accurately, both the strength and stress of the 
beams : bridges apparently strong, and perfect in construction, 



256 SCIENTIFIC AGRICULTURE. 

sometimes fall by their own weight: in such cases there is an 
unnecessary violation of a philosophical principle of which no 
mechanic should be ignorant. In buildings and machinery, 
materials should never be loaded to the hmits of elasticity, 
nor even to the extent of altering their form : if this is done, 
brittle bodies fly to pieces, and elastic and ductile ones change 
form without separation of their parts, sufficiently in some 
cases to destroy the structure or diminish the efficacy of 
machinery. For suspension bridges, the strongest material for 
spanning a wide stream is cast steel wire, — the next strongest 
is malleable iron, and least of all metals, lead. A piece of 
cast steel wire one-eighth of an inch in diameter, -will sustain 
a weight of 16,782 pounds: or 4,931 feet of its own length; 
malleable iron wire of the same size, 9,008, or 2,467 feet of 
its own leng-th; lead wire of the same size sustains only 228 
pounds, or 42 feet of its own length. 

Of the different kinds of wood, the strongest are, the ash, 
oak, teak, beech and larch, — the strongest of these is the ash. 

We see by these few facts in relation to mechanical philoso- 
phy, that almost every praclical mechanical operation can be 
reduced to scientific rules, and the result calculated with 
mathematical certainty before the work is commenced. We 
see also how much more easily and economically many opera- 
tions might be performed, and how much disappointment and 
money might be saved by a knowledge of this branch of sci- 
ence, to the visionary inventors of patent rights, the only fault 
of which is, that they refuse obstinately to perform any part of 
the work designed for them, — and the greatest misfortune of 
whose inventors is their ignorance. A knowledge of mechani- 
cal philosophy is indispensible to the accomphshed mechanic or 

agriculturist. 



GLOSSARY. 



Agriculturey tlie science and art of productive farming. 

Affinity y attraction — that force wliich causes two bodies of dif- 
ferent propei-ties to unite and form a compound. 

Annual, yearly. 

Aerial, pertaining to the air. 

Axis, the centre or point on which a body does or may revolve. 

Acotyledonous, without a cotyledon. 

Ajypendage, something added. 

Albumen, an organic principle resembling white of eggs. 

Altitude, height or elevation. 

Arterial, pertaining to the arteries. 

Acerose, needle shaped. 

Axillary, growing in the angle between the stem and leaf 

Arragonite, a simple mineral composed of carbonate of lime. 

Ame7it, flowers collected on chaff-like scales and an'anged on a 
slender stalk. 

Assimilate, to become similar. 

Anemia, want of blood — in botany want of sap. 

Absorption, the act of imbibing or absorbing. 

Anthracite, a species of mineral coal. 

Aluminum, a metalic earth, the base of alum. 

Albite, a species of feldspar. 

Arseniate, a salt of arsenic. 



258 GLOSSARY. 



Asbestos, a fibrous incombustible material. 

Analysis, separating the elements of a compound. 

Azure, sky blue. 

Alluvium, the sediment of rivers, such as sand, vegetable mat- 
ter, mud, (fee. 

Augite, a simple mineral of a dark green or black color, found 
as a constituent in many volcanic rocks. 

Amygdaloid, one of the trap rocks through wliich are scattered 
agates and simple minerals. 

Agate, a translucent silicous mineral of many varieties. 

Apocretiic acid, an acid found in peat and humus soils. 

Atmosphere, the air which we breathe. 

Aggregate, the sum of several particulars. 

Anhydrous, destitute of water. 

Aurora Borealis, Northern Liohts. 

Aqueous, watery. 

Aerolite, a meteoric stone falling through the air. 

Alternate, leaves growing on opposite sides of the stem at dif- 
ferent distances, but not opposite each other, are alternate. 

Alburnum, sap-wood. 

Accretion, increasing in size by the addition of new matter. 

Alchemy, the pretended science from which chemistry origina- 
ted : its operations consisted in trying to change the baser 
metals into gold ; to find a universal solvent and a remedy 
for all diseases. 

Attenuation, the act of maldng fine, tliin, minute. 

Angle of incidence, the angle at which a moving body strikes 
another. 

Angle of reflection, the angle at wliich a moving hody leaves 
or bounds from another. 

Aquafortis, nitric acid. 

Aqua-ammonia, spirit of hartshorn. 

Acrid, sharp, pungent, biting. 

Acid, sour, having chemical properties opposite to alkalies. 



^ 



GLOSSARY. 259 

AlJcali, in common language, lye. 

Apoiheme, extractive matter. 

Adjective color Sy siicli as require a mordant. 

Alizarine, the basis of the red coloring principle. 

Arable, fit for tillage or cultivation. 

Avidity, greediness, eagerness. 

Asholine, one of the elements of soot. 

Arctic, pertaining to countries north or south of the arctic 

circles. 
Animalculce, animals too minute to be seen with the eye. 
Anthelia, luminous rings seen in the sky opposite the sun. 
Adhesion, sticking together. 
Amiattb, a yelloAvish coloring matter from the plant called 

Bixia Orleana. 
Botany, the science of plants. 

Boulder, a rounded fragment of rock lying on the surface. 
Blowpipe, an instrument used in chemical experiments. 
Bole, a species of reddish earth. 

Bituminization, the process of furnishing bituminous coal. 
Biennial, once in two years. 
Biternate, twice ternate, — two petioles, each bearing three 

leaves. 
Barometer, an instrument for measuring the pressure of the 

atmosphere. 
Base, the substance which combines with an acid to form a 

salt 
Bed, a term used in Geology to denote the extent of a stratum 

of coal or other rock. 
Basalt, a dark green rock divided in columns. 
Butyric acid, acid of butter. 
Climatology, a treatise on climate. 
Caloric, the agent which produces heat. 
Coalesce, to unite or run together. 
Condense, to make more dense. 



260 GLOSSARY. 

Clouds, floating particles of water or other matter. 

Congeal, to freeze or harden. 

Crystalization, the act of forming crystals. 

Concentric, having a common centre. 

Cohesion, the force which holds the particles of bodies together 

Corona, a luminous circle round the sun or moon. 

Cleavage lolanes, the flat surface formed by the cleavage of 

rocks. 

Continuity, unbroken, continuous texture. 

Carboniferous, any bed or rock containing coal. 

Coral, a maritime production composed of Ume, and the habi- 
tation of insects. 

Cuhoidal, in the form of a cube ; square. 

Columnar, having the form of columns. 

Chalcedony, a species of quartz-hke mineral. 

Calcareous spar, crystalized carbonate of Hme. 

Crater, the opening of a volcano through which its eruptions 
take place. 

Chlorite, a simple mineral of a gTeen color. 

Crucible, an earthen or metallic pot in which ores are melted 
and purified. 

Crenic acid, an acid found in peat and humus soils. 

Calcareous, Umy, composed mostly of hme. 

Caustic, corrosive, biting, burning. 

Calcine, to burn. 

Cuticle, the outside bark or skin. 

Capillarity, the property of absorbing by capillary attraction. 

Carbonate of potash, pearlash. 

Chlorine, a simple substance. 

Calorific, producing heat. 

Capacity for caloric, power of containing latent heat 

Combustion, the act of burning. 

Conductors, substances which conduct caloric or electricity. 

Carbon) charcoal. 



GLOSSARY. 2G1 

Clarify, to make clear or clean. 

Carhonic acid, a compound of carbon and oxygen. 

Complex, having many component parts. 

Coniferous, bearing seeds in cones, like the pine. 

Carmine, a coloring matter of a pink color. 

Casein, an organic element the basis of cheese. 

Caramel, a substance produced by heating sugar. 

Carhuretted hydrogen, a gas composed of carbon and hydrogen. 

Carhonic oxide, a gas composed of carbon and oxygen. 

Corrosive, ha\'ing the property of corroding and destroying. 

Cellular, composed of small cells. 

Cryptogamous, having flowers too minute to be seen with the 
naked eye. 

Cotyledon, a seed lobe. 

Carnivora, the class of animals which hve on flesh. 

Crucifor^n, having the form of a cross. 

Calyx, a cup, the bottom part of a flower. 

Corolla, the closed leaves of a flower. 

Crude, raw, immature. 

Cordate, heart shaped. 

Chlorophylle, the green coloring matter of plants. 

Cambium., the descending sap which fonns wood. 

Centripetal, tending towards the centre. 

Cereals, tlie white straw grains, as wheat and rye. 

Chrysolite, a simple mineral, of gold color. 

Centrifugal, tending to recede from the centre. 

Corymb, a cluster of flowers whose stalks spring from different 
heights, and form a flat top. 

Cyme, a cluster of flowers whose stalks rise from a common 
centre, and afterwards subdi\ide irregularly. 

Contagion, an infectious or pestilential disease which is com- 
municated by contact or through the atmosphere, from one 
animal or plant to another. 

Conglomerate, a species of rock composed of sand, gravel, and 
fragments of other rocks. 



Colostrumy first niilk after birth of calf. ^^^^^^^H 

Curd, the cheese of milk. ^^^^H 

Comet, a luminous meteor with a tail or train. ^^H 

Coagulate, to become thick, clotted. « 

Capric acid, acid from butter. m 

Caproic, acid, acid from butter. fl 

Denude, to make naked or bare. ■ 

Dunes, hills of blown sand. '« 

Disintegrate, to separate into integral parts. M 

Ductile, capable of being drawn into wire. m 

Dilute, to make thin or reduce in stFength. ■ 

Deciduous, falling off in the usual season : not persistent. 9 
Dissemination, the act of sowing or scattering. ■ 

Dilate, to expand, extend, enlarge. 9 

Digestion, the act of assimilating food to the body. 1 

Digitate, divided like the fingers. m 

Dip, the inchnation of a stratum of rock from the horizon. !■ 
Dyke, a mass of rock which appears to have been injected into 

the fissures of other rocks. 
Drift, masses of sand or other matters driven together by 

water. 

Deleterious, injurious, noxious. 

Duramen, the inside, brown heart of wood of forest trees. 
Decompose, to separate into parts or elements. 
Data, knoAvn or admitted facts or principles. 
Deutoxide, a chemical compound containing two proportions 
of oxygen. 

Daguerreotype, a process of taking pictures by means of light. 

Dynamical, pertaining to strength or power. 

Deliquiesce, to dissolve gradually by attracting and absorbing 

moisture from the air. 
Distillation, separating essential oils or alcohol from other 

matters, by means of heat. 
Diurnal, daily, occurring daily. 



GLOSSARY. 263 

Disinfecting, purifying and preventing contagion and infection. 

Extant, now in use. 

Extirpate, to destroy or eradicate, 

JExcavate, to dig or wear out a hollow or cavity. 

Excrements, matters voided or excreted by animals. 

JSndogens, plants which grow from the inside. 

JElectricity, a principle in nature usually called lightning. 

Elasticity, power of resuming form after compression. 

Elective affinity, that affinity which causes an acid or alkah ta 

abandon one with which it is already united, and unite with 

another. 
Ether, a subtil matter which is much hgliter than air, and 

supposed to exist beyond the hmits of the atmosphere. 
Emit, to send oftj give out or discharge. 
Expansion, the act of enlarging or increasing in bulk. 
Equisetum, a plant of the rush family. 
Equivalent number, the particular quantity of any substance 

required to combine with or saturate another substance. 
Emanate, to issue or flovf from. 
Electric, a substance capable of giving off electricity. 
Electrical repulsion, that property which causes bodies in the 

same state of electrical excitement to separate: opposite 

attraction. 
Exude, to run out or issue fi'om. 
Equilibrium, balance of forces and properties. 
Epiphytes, plants growing upon the trunk and branches of 

other plants and derive nourishment mostly from the air. 
Epidermis, outside sldn or bark. 
Excrete, to eject or throw out. 
Embryo, the germ of a plant or animal. 
Elliptical, an oval figure with pointed ends. 
Exogens, plants which grow by layers on the outside. 
Exhalation, breathing out, giving off, emitting. 
Evolution, emission, giving off, discharging. 



264 GLOSSARY. 

Element, a component part, first principle. 

Equator y an imaginary line dividing the earth into two halves ; 

the equinoctial line. 
Effloresce, to become a dry powder. 
Eremacausis, slow combustion or decay. 
Evaporation, becoming volatile, flying off with the air, drying up. 
Escarpment, a steep ledge of rocks. 
Eurite, a white mineral. 
Eject, to throw out, discharge. 
Effervesce, to foam, bubble, ferment. 
Fasicle, a small bundle. 

Flora, the goddess of flowers, a flower or book of flowers. 
Functional, pertaining to the oflfice or use of a part of any 

organism. 
Filament, the slender, thread-like part of the stamen. 
Fibrils, minute branches of roots. 

Fibrous, composed of fibres. 
Fusiform, spindle-shaped, tapering. 
Fasciculated, collected in heads or bundles. 
Fundamental, original, elementary, first principle. 
Fructification, the flower and fruit with their parts, the act 
of makintv fruitful. 

o 

Fapirenheit, the inventor of the thermometer which bears 

that name. 
Fault, a cleft or fissure in a rock. 
Fossil, the remains of animals and plants found buried in 

the earth. 

Formation, a group of any kind of rocks referred to a com- 
mon origin or period. 
Fossiliferous, containing fossils. 
Fissure, a crack or cleft. 
Fuse, to melt, become fluid from heat. 
Faggot, a bundle of sticks or brush. 

Friable, easily crumbled or pidverized, 
12 



GLOSSARY. 265 

Pertilizers, substances used to enrich the soiL 

Focus, the point at which rays of light or heat meet. 

Fluor spar, a mineral compound of lime and fluoric acid. 

Fibre, a slender, thread-like organ or substance* 

Fumes, vapor, gas or smoke* 

Freezing point, this is placed at 32° Fahrenheit. 

Feldspar, a simple mineral which constitutes a principal ingre- 
dient of most rocks. 

Fire damp, hght carburetted hydrogen. 

Fibrine, the colorless part of the blood which when separated 
from it becomes jelly-lilve. 

Formula, rule or receipt. 

Geology, the science of the earth's structure, &c. 

Graphite^ black lead. 

Galvanism, a species or modification of electricity. 

Glutinous, sticky, \i[scid, ha\dng the characters of glue. 

Generate, to produce or create. 

Gelatine, a proximate piinciple in plants and the bodies of ani- 
mals, usually called jelly. 

Guano, a species of manure composed mostly of the excre- 
ments of sea fowls. 

Granite, an unstratified primary rock. 

Greenstone, a variety of trap rock composed of hornblende 
and feldspar. 

Gneiss, a primaiy stratified rock composed of the same mate* 
rials as granite. 

Garnet, a simple crystalized mineral, generally of a deep red 
color. 

Gypsum, plaster of paris, sulphate of lime. 

Graphic granite, is a species of granite in which the quartz Is 
so ari'anged as to give the surface the appearance of having 
letters. 

Gorge, a deep fissure or valley. 

Gyration, turning in a circular or spiral direction. 



;fES| 



266 GLOSSARY. 

Glossology, tlie application of names to the various organs of 

plants. 
Granulated, consisting of small grains, granules, or masses. 
Genus, the subdivision of an order. 
Gland, an organ in animals and vegetables which performs 

function of secreting a fluid. 
Germination, the unfolding of the seed and the development 

of the embryo. 
Geine, a substance obtained from decayed wood, and containing 

an acid called the geic acid. 
Granular, consisting of grains, 
Graywacke, an ancient fossiliferous rock, generally of a gray 

color. 
Gravity, weight: specific gravity, the weight of a particular 

body compared with some standard. 
Gas, an elastic fluid or air. 
Gelatinous, containing gelatine. 
Gastric juice, the fluid which performs digestion. 
Homogeneous, of the same nature, consisting of similar parts, 

all alike in structure. 
Hornblende, a simple mineral of dark green or black color. 
Humid, moist, wet. 

Harmattan, a dry easterly wind in Africa. 
Haziness, foggy, smoky, misty. 

Horizon, the hue where the earth and sky appear to meet 
Hydrogen, a gas, the lightest of all known bodies. 
Hues, tints, colors. 

Hurricane, a violent storm or tempest. 
Halo, a circle appearing around the sun, moon, or stars. 
Hypothesis, a supposition or theory assumed but not proved : 

used for the purpose of argument. 
Hexagonal, six-sided : having six sides and six angles. 
Hydracid, an acid formed by the union of a substance with 

hydrogen without oxygen. 



GLOSSARY. 267 

Hematoxyline, the coloring principle of logwood 
Hydrate^ a compound containing water. 
Humic acid, an acid obtained from humus. 
Herbaceous, herb-like, not woody. 
Herbarium, a book in which dried plants are preserved. 
Humus, decayed vegetable matter. 
Hypothetical, assumed without proof 
Hydrostatic, pertaining to water at rest, &c. 
Imbibe, to take in, absorb. 
Irrigation, the act of watering, moistening. 
Incineration, the act of reducing to ashes. 
Intersect, to meet and cross each other. 

Isomeric, bodies wliich differ in properties but agree in com- 
position. 

Inter stratified, stratified between or among other bodies. 

Infusible, that cannot be fused or melted. 

Incas, inhabitants of Peru and some other parts of S. America. 

Inflate, to blow up, fill with wind. 

Isothermal lines, lines which pass through points on the surface 

of the earth at which the mean temperature is equal 
Isochimenal lines, fines passing through points on the earth at 

which the mean temperature of the winter is equal 
Intertrojncal, between the tropics. 
Ignis fatuus^ Jack O 'Lantern. 
Inverted, turned upside down. 
Igneous, rocks, such as have been melted by fii*e or volcanic 

heat. 

Infusoria, animalcules too minute to be seen by the naked eye. 

Interlace, to tangle or lace together. 

Inflorescence, the manner in Avhich flowers are connected with 

the plants. 
Indigenous, native o^ or growing wild in a country. 
Joiiit, the parting fines in rocks, often at right angles with the 

planes of stratification. 



1 



208 GLOSS ART. 

Kaolin, a species of potter's clay. 

Kid, the young goat. 

Lignite, wood converted into a kind of coal. 

Lava, the melted stone which is thrown out of volcanoes. 

Lichens, cryptogamic plants, of a crusty texture growing on 

rocks and the trunks and branches of trees. 
Lenticular, having the form of a lens. 
Longevity, leng-th of life. 
Laticiferous, the system of vessels in the bark of plants, which 

circulates their fluids. 
Latex, the fluid formed from the sap, and which nouiishes all 

parts of plants. 
Lanceolate, in the form of a lancet. 

Lyrate, pinnatified with a large roundish leaflet at the end. 
Linear, long and narrow with parallel sides, as in the leaves of 

the grasses. 
Leguminous, having legumes or pods, as the bean and pea. 
Liber, the inner bark of plants. 
Lamina, layers, thin plates or leaves. 
Longitude, the distance of places on the globe in an east and 

west direction. 
Latitude, distance or degTces north and south. 
Laminated, in lamina, layers or leaves. 
Lunar, pertaining to the moon. 
Limjnd, pure, clear, transparent: thin, when used in reference 

to some fluids. 
Leek, a wild onion, a plant of the allium family. 
Lactic acid, acid of milk. 
Lycopodium, a plant of the moss family. 
Marine, pertaining to the sea. 
Microscopic, objects which are too small to be seen without the 

aid of the microscope. 
Macerate, to soak, dissolve. 



GLOSSARY. 269 

Maximum, the greatest number or quantity attainable in any- 
given case. 

Magnetism, the power or force which causes the magnetic 
needle to point north and south. 

Molecules, the ultimate or minute paiiicles of matter. 

Mirror, a looking glass. 

Mercury, quicksilver. 

Mucilage, a slimy fluid, one of the proximate elements of plants. 

Mordant, any substance used by dyers to set colors, or render 
them permanent 

Miist, the juice of grapes which has not fermented, new wine. 

MetamoiykosiSy change, transformation. 

Meteorology, the branch qf science which treats of changes of 
weather and other atmospheric phenomena. 

Meteor, any appearance or phenomena observed in the atmos- 
phere. 

Mean temperature, that point which lies midway between the 
two extremes of heat and cold. 

Mist, fog, vapor, 

Marithne, relating or pertaining to the sea. 

Monsoon, a periodical wind which blows six months in one 
direction, and then changes and blows six months in the 
opposite direction. 

Moor, a marsh or fen, or land ovei^rown with heath and other 

shrubs. 
Mirage, an optical illusion described in meteorology. 
Mineral, in common language, the metals and rocks. 
Metalloid, a name applied to some of the metallic bases of 

the earths. 
Mica, a rock which is divided or laminated in its shining 

scales, and of various colors. 

Metamorphic, rocks which have been altered by the action 
of fire. 



270 GLOSSARY. 



Muriate of magnesia, a salt formed by the union of magne- 
sia with muriatic or hydrochloric acid. 

Mammalia, vertebrated animals, Avhich have warm blood, 
breathe by means of lungs, bring forth living young and 
nourish them by milk. 

Membrane, a thin delicate skin. 

Midrib, the main or middle rib of a leaf, running from the 
base to the point. 

Medullary, pertaining to the pith or marrow. 

Morphology, that part of botany which treats of the forma- 
tion and metamorphosis of organs. 

Malleable, a metal which can be hammered and drawn out 
into various forms by the hammer, as iron. 

Nutrient, nourishing, or pertaining to nutrition. 

Noxious, hurtful, injurious, imwholesome. 

Nomenclature, a system of naming or applying technical 
terms in any art or science. 

Nutritiorii, the act or process of supplying the proper mat- 
ter for the gTOwth of animals and plants. 

Nitric acid, aquafortis. 

Nitrate of potash, salt petre. 

Node, a knot or protuberance. 

Nocturnal, nightly, occurring every night. 

NicJcel, a grayish white brittle metal. 

Nodular, havino' nodes or knots. 

Napiform, resembhng a turnep in fonn. 

Ovary, a name in botany given to the outer covering of 
the genu. 

Ovules, little' eggs, the rudiments of seeds which the germ 
contains before its fertilization. 

Orbicular, round, circular. 

Organography, a description of the organs of plants. 

Organic, composed of various parts or organs which perform 
separate offices. ^ 



GLOSSARY. 271 

Oxidize, to become rusty or combine with oxygen. 
Observatory, a place or building for making observations on 

the heavenly bodies, 
Opake, not transparent, not pervious to rays of light. 
Optical, pertaining to the eye, to vision, or the science of optics. 
Orhit, in astronomy, the path of a comet or planet. 
Outcrop, the naked ends of strata of rock which protrude 

above the surface of the earth, as on the side of a hill. 
Oolite, a hmestone composed of rounded particles like the 

eggs of fish. 

Organic remains, the fossil remains of plants and animals. . 
Olivine, an olive colored simple mineral often found in grains 
and ciystals in basalt and lava. 

Oxide, a chemical compound of metals with oxygen, &c. 
Oxygen, a gas. 

Oxalate, a salt composed of oxalic acid and a base. 
Oxalic acid, an acid obtained from sorrel. 
Ordure, excrement, faeces, manure. 

Permeate, to penetrate or pass through the pores of a body. 
Phosphuretted Hydrogen, a compound of phosphorus and 
hydrogen. 

Poiidrette, a manure prepared from ordure. 

Philosopher's stone, an imaginary mineral sought by the 

alchymists, which was supposed to be capable by mixture 

with the baser metals of transmuting them into gold. 
Proxi?nate, near; "proximate elements," those elements of 

plants, such as starch, gum, &c., which are composed of the 

immediate elements, ^iz : the gases and mineral matters. 
Protoxide, a compound containing one proportion of oxygen. 
Photographic, pertaining to light; photographic pictures are 

taken by hght. 
Phosphorescence, a peculiar luminous matter without fire or 

combustion, as the Hght given out by phosphorus, decayed 

wood, putrifying flesh, &c. 



272 GLOSSARY. 

Parahola, a conic section arising* from cutting a cone by 
plane parallel to one of its sides. 

Pris7n, in optics, a triangular glass instrument for separa- 
ting tlie rajs of light. 

Polarity^ that property which causes one end of a body to 
repel, and the other to attract, as in bodies magnetized 
or electrified: pointing towards the poles. 

Putrefaction, decomposition or decay of organic bodies. 
Pungent, biting, hot, sharp. 
Ponderable, possessing weight. 
Precipitate, to throw down or separate. 
Phosphates, compounds containing phosphorus. 
Parallelism, the state or quality of being parallel 
Petrify, to become stone. 
Pebble, a small stone. 
Plutonic, pertaining to subterranean heat 
Porphyry, an unstratified igneous rock. 
Pegmatite, primitive granite rock. 
Pumice stone, a species of lava. 
Plumbago, black lead, graphite. 
Pulverulent, consisting of fine dust or powder. 
Phenomena, an appearance. 

Phase, an appearance, exhibited by the illumination of the 
moon or other planets. 

Polar elevation, height of latitude, or approach towards the 
poles. 

Pestilential, infectious, spreading pestilence. 

Phosphorus, a simple combustible body of a yellowish color, 

and the consistence of beeswax. 
Physical, pertaining to matter or physics. 
Parhelia, mock suns, or luminous spots near the sun. 
Pistil, the- central organ of most plants consisting of the 

stigma, style and germ. 



I 



GLOSSARY. 273 

Perianth, a sort of calyx, the floral envelops, consisting of 

the calyx and corolla, which are placed around the pistils 

and stamens. 
Pollen, the dust contained within the anthers of flowers, and 

necessary to fructification. 
Placenta, a part of the ovary to which the ovules are attached. 
Pericarp, the seed covering. 

Parasite, a plant or animal which gTOWS on another. 
Perennial, lasting more than two years, evergreen. 
Phenogamia, plants which bear visible flowers. 
Petal, a flower-leaf which is part of the corolla. 
Plumule, the ascending part of a germinating plant. 
Perforate, to make a hole, ha\ing holes, to pierce. 
Parenchyma, the principal and proper substance of any organ 

in a plant or animal. 
Pervious, porous, or capable of being penetrated. 
Pellicle, a thin skin, film or crust. 
Pyrogen, the matter or generator of electricity. 
Porcelain, a fine kind of earthen ware. 
Peat, decayed and decaying vegetables, usually buried below 

the surface of the ground. 
Peduncle, the stem which bears the flower and fi'uit 
Panicle, a loose, irregular bunch of flowers, as in the oat. 
Propagate, to produce, or multiply by shoots, &c. 
Physiology, the science which explains the laws of life and 

the uses and offices of all the various organs of plants 

and animals. 
Pulp, the soft juicy part of fruits and benies. 
Paraselenae, luminous rings about the moon. 
Quartz, a simple mineral composed of silex or flint. 
Quartzose, containing quartz. 
Quiescent, in a state of quietude or repose. 
Quadruple, four times, four fold. 
Badiate, to sliine, to proceed in direct lines fi:om a point, like 

rays cf fight or heat 



274 GLOSSARY. 

Repulsion, the act of repelling or driving off, as in bodies in 
the same electrical state : opposed to attraction. 

Rarity, the opposite of density, thin, hght 

Refrangibility, capable of being refracted. 

Respire^ to breathe. 

Residual, remaining after a part is taken, sediment which sub- 
sides from a watery mixture. 

Reagent, a substance employed to precipitate another from 
solution, or to detect the presence of some other substance. 

Rape, a plant of the genus brassica, allied to the cabbage. 

Ramify, to branch off, divide. 

Radiation, the act of radiating, throwing off rays. 

Refrigerating, producing cold. 

Reverberate, to return, rebound, resound, re-echo. 

Rays of lights the brilliant luminous lines wliich proceed 
or radiate from a luminous body. 

Ratify, to make less dense, to make thin or hght. 

Rarifaction, the process of rarifying, making more porous by 
expansion. 

Refraction, the act of bending or breaking, deviating from a 
direct course, as in rays of hght 

Receptacle, the end of the flower-stalk to which the organs 
of fructification are usually attached. 

Ramous, branching, having lateral divisions. 

Ramification^ branching, minute division. 

Ravine, a deep hollow or valley worn out by water. 

Ruby, a precious stone, a simple mineral of a carmine red 

color. 
Rachis, the common stalk to which florets and spikelets are 

attached, as in the grasses and wheat 
Raceme, a cluster, that variety of inflorescence in which the 

flowers are arranged by simple pedicels on the sides of a 

common peduncle, as the currant. 
Respiration, breathing, or the, act of absorbing or inhahng 

and exhahng carbonic acid and oxygen. 



li 



GLOSSARY 275 

Mosacea, an order of plants, including tlie rose tribe. 

Hadicle, the descending part of a germinating plant, a small 
root. 

JRudimental, consisting of the first principles, or simple ele- 
mentary parts. 

Hemform, kidney shaped. 

Rennet, prepared stomach of the calf used in cheese. 

Rancid, strong, tainted. 

Resinous, containing resin or pitch. 

Repel, to throw o£f or resist 

Succulent, juicy. 

Sjiontaneous, produced without planting or cultivation. 

Syi^Jion, a bent tube. 

Smirian, the lizard family. 

Strippings, last milk. 

Safety lamp, a lamp surrounded by wire gauze, invented by 
Dr. Davy to prevent explosions from the ignition of gas 
in coal mines. 

Silicate, a salt containing siUca united to a base. 

Silecious, containing silex. 

Stercology, the science of manuring, enriching, or impro- 
ving; the soil. 

Smoulder, to burn and smoke without vent. 

Sewer, a drain to convey off water underground. 

Sulphate of iron, green vitriol, copperas. 

Spurry, a plant of the genus spergiila, allied to chickweed 
and tares. 

Spiral, in the form of a screw, gyratory like the thread of 
a screw. 

Suhordinate, of minor importance, a secondaiy or inferior 
part. 

Synthesis, the act of combining, contrar}'- to analysis. 

Spectrum, a \dsible image continuing after the eyes are 
closed: the seven primary colors constitute the solar spec- 
trum. 



276 OLOSSARY. 

Statical, in a state of rest, the branch of mechanics which 

treats of bodies at rest. 
Sterile, barren, unproductive. 

SolveiU, a substance or fluid which dissolves other substances. 
Solar, pertaining to the sun. 
Sublimated, brought into a state of vapor by heat. 
Stameny a slender thread*Hke organ in the centre of flowei-s. 
Summit, the apex or top. 
Stigma, the summit or top of the pistil. 
Style, the part of the pistil between the stigma and germ. 
Stomata, mouths, or orifices. 
Spongioles, the minute spongy suckers or extremities of 

roots, 
Sjpores, the seeds of cryptogamous plants, bodies analagous 

to the pollen grains of flowering plants. 
Sepal, a leaf of the calyx. 
Sagittate, arrow form. 
Segment, a part or principal division of a leaf, calyx, or 

corolla. 

Stellate, star form. 

Succulent, juicy. 

Shale, a solid form of clay, which usually divides into lamina. 

Saccharine, sweet, containing sugar. 

Spadix, an elongated receptacle of flowers, commonly prO' 
ceeding from a spathe. 

Scoria, volcanic cinders. 

Silicon, the substance which combined with oxygen consti- 
tutes silicic acid or flint. 

Sajyphire, a hard mineral, consisting of crystalized alumina: 
it is of various colors; the blue being generally called 
the sapphire; the red, the oriental ruby; the yellow, the 
oriental topaz. 

Saline, salt, containing some salt 
Sodium, the metallic base of soda. 



GLOSSARY. 277 

Steatite, soap-stone, a liydrated silicate of magnesia and alu- 
mina 

Snow-line, the lowest point on mountains at "vvliicli there is 
perpetual snow. 

Subterranean, underground, below the earth's surface. 

Submerge, to plunge under water, to overflow. 

Strata, layers of rock. 

Spherule, a little sphere or ball. 

Simoon, a hot suffocating wind, that blows occasionally in 
Africa and South America. 

Sirocco, a pernicious wind that blows from the south-east 
in Italy. 

Saluh'ious, healthful, fcivorable to health. 

Supernatural, miraculous, out of the usual course of nature. 

Solar sp)ectrum, the seven primary colors as seen in the 
rainbow. 

Stratified, arranged in strata or layers. 

Silurian, a series of rocks forming the upper subdivision of 
the sedimentary strata found below the old red sandstone, 
and formerly designated the graywacke series. 

Scape, a stalk which springs from the root, and supports 
flowers and fruit, but no leaves. 

Saturate, to fill with a fluid, absorb, soak. 

Sedimentary rocks, are those which have been formed by 
their materials havino- been thrown down from a state of 
suspension or solution in water. 

Syenite, a kind of granite so called because it was formerly 
brought from Syene in Egypt 

Serpentine, a rock usually unstratified, containing much mag- 
nesia, and often speckled of various colors, like a serpent's 
back. 

Sculptu7'e, the art of carving wood or stone into the images 
of men or animals. 

Stucco, a fine white plaster, to plaster with stucco. 



278 GLOSSARf. 

Stalactite, a variety of carbonate of lime in tlie form of 
icicles, produced by the filtration of water containing lime 
in solution, from the crevices of rocks in the roofs of cav- 
erns. 

Stalagmites, are silimilar to stalactites, but formed by the 
dropping of water on the floors of caverns, and having 
their points upwards. 

Torrid, the countries within the tropics, hot. 

Twilight, the hght at the close of day after sunset and be- 
fore dark. 

Tortuous, crooked, convoluted. 

Tertiary, a series of sedimentary rocks, lying above the pri^ 
mary and secondary, and having characters which distin- 
guish them from these two classes. 

Trachyte, a variety of lava essentially composed of green- 
stone: it frequently contains detached crystals of feldspar, 
and sometimes hornblende and augite. 

Titaniferous, an iron ore containing titanium. 

Talc, a species of magnesian earth, consisting of smooth 
shining lamina, translucent or transparent. 

Transparent, admitting rays of light to pass through. 

Transverse, crosswise, across. 

Terrestrial, belonging to, or pertaining to the earth. 

Tillage, includes all mechanical operations on the soil. 

Tropical, belonging to the ti'opics. 

Torrid zone, the hot country included between the Tropic 
of Cancer, and the Tropic of Capiicorn. 

Tornado, a high wind, a whirlwind. 

Theory, an exposition of the principles of any science; the 
science without the art or practice. 

Tissue, connection of organization, the proper substance of 
an organ. 

Terminal, situated at the end. 

Thyrse, a loose iiTegular bunch of flowers. 



GLOSSARY. 279 

Tenacity^ toughness, having strong cohesion. 

Tap root, the main root, the axis. 

Tube)', a fleshy knob or tumor on a root. • 

Tri/olimn, the genus of plants to which clover belongs. 

Ternate, leaves which are arranged in threes are called 
ternate. 

Transmit, to permit to pass, to convey through. 

Tint, shade, hue, color. 

Transition, rocks which appear to have been formed while 
the earth was in a state of transition, from a state of 
desolation to a habitable condition. They have a textui*e 
partly mechanical and partly chemical. 

Unguentum, ointment, grease. 

Udder, the bag of the cow. 

Urea, the principal element, next to water, in the compo- 
sition of the urine. 

Ulmic acid, a substance formed by the action of acids on 
sugar. 

Unconsolidated, soft, not consolidated. 

Umbel, a kind of infloresence in which the flower stalks 
diverge from one centre, as the wild parsnep. 

Velocity, rate of motion. 

Vitriolic, from vitriol. 

Vitreous, glassy, containing glass. 

Volcano, a burning mountain. 

Vision, sight, the act of seeing. 

Veins, cracks or fissures in rocks which are filled with sub- 
stances difierent from the rock, either mineral or earthy. 

Volcanic, pertaining to volcanoes, produced by volcanoes. 

Vertical, perpendicular, overhead. 

Vapor, mist, fog, small particles of water. 

Vesicles, small particles or drops. 

Verticil, whorled, having leaves or flowers in a circle round 
the stem. 



280 GLOSSARY. 

Volatile, evaporating or flying off easily. 

Vascular, made up of vessels, or full of vessels. 

Vasiform tissue, is made up of large tubes. 

Venation, the arrangement of the ribs or veins in leaves. 

Viscid, stringy, sticky, slimy. 

Verticillate, whorled. 

Verdure, foilage, herbage. 

Vibrate, to swing or oscillate. 

Vacuum, an empty space, a space from which the air has 

all been removed. 
Vitality, life, the vital or living principle. 
Vital functions, those functions or actions w^hich are indis- 

pensible to organic 'hfe. 
Vetches, a leguminous plant allied to the pea, bean, and 

lentil. 
Whey, watery part of milk. 

Warping, a process in agriculture similar to irrigation. 
Wealden, a fresh water group of rocks, composed of clay, 

lime, marl, &c. 
Zigzag, in a crooked direction, forming short angles. 
Zenith, that point in the sky or celestial hemisphere which 

is vertical to the spectator. 
Zanthine, a substance found in urinary calculi. 
Zeolite, a mineral composed of silica, alumina and liijie. 



INDEX, 



Analysis, - - - ." - 23 

Affinity, chemical, - - - - 28 

Affinity, simple, - - - - - 28 

Affinityj elective, - - - ■ 29 

Attraction, chemical, - - - - - 28 

Atmosphere, - - - - " ^* 

Acid, nitric, - - • - - -50 

Aquafortis, - - - - . - 50 

Ammonia, ------ 51 

Acids, properties of - - - - ^^ 

Alkalies, properties of - - - -56 

Albumen, - • - - - ^1 

Acids, vegetable, - - - - - 64 

Alkahes, vep-etable, - - - - 64 

Apotheme, - - - - - -oa 

Alizarine, - - - - " "^ 

Alluvium, - - - - " - /9 

Amygdaloid, - - - - - 85 

Appendages of plants, - - - - 98 

Anther, 101 

Albumen, - - - - - -103 

Aerial roots, - - - - - 1^7 

Annual roots, - - - - -107 

Alburnum, - - - - - H^ 

Absorption, - - - - - -119 

Agriculture, influence of on chmate, and fall of rain, 136 
Aerolites, ------ 158 

Aluminum, - - " - - 1^0 



282 INDEX. 

Alum, - - - - - - 160 

Analysis of soils, - - - - 230 

Analysis of soils to determine the quantity of vegetable 

matter, - - - - - 231 
Analysis of soils to determine the quantity of sand and 

clay, - - - - - - 231 

Analysis of soils to determine the quantity of water, 231 
Analysis of soils to determine the quantity of humic 

acid, ------ 232 

Analysis of soils to determine the quantity of ulmic 

acid, ------ 232 

Analysis of soils to detenuine the quantity of crenic 

and apocrenic acids, - - . - - 232 

Analysis of soils to determine the quantity of lime, 233 

Analysis of soils to determine the quantity of silica, 238 
Analysis of soils to determine the quantity of oxide 

of iron, ------ 233 

Analysis of soils to determine the quantity of diflfer- 

ent salts, ------ 233 

Analysis of a fertile soil, - - - 234 

Analysis of a barren soil, - - - - 234 

Aurora Borealis, - - - - 149 

Analysis of beech and oak ashes, - - - 210 

Ashes of coal, peat, &c., as manures, - - 211 

Analyses, tables of, . - - - 218 

Analysis of wheat, - - - - 119 

Analysis of barley, - - • - -220 

Analysis of oats, - - - _ 220 
Analysis of rye, - - - - -221 

Analysis of peat, - - - - 221 

Analysis of coal ashes, - - - - 252 

Analysis of bean and pea, - - - 222 

Analysis of turnep and potato, - - - 222 

Analysis of carrot and parsnep, - - - 233 

Analysis of grass and clover, - - - 223 

Analysis of silica plants, - - - 224 

Analysis of hme plants, - - - - 224 

Analysis of potash plants, - - - 225 

Analysis of feces of horse, - - - - 225 

Analysis of urine of horse, - - - 225 

Analysis of faeces of cowj - - - - 226 



INDEX. 283 

Analysis of urine of cow, - - - 226 

Analysis of human faeces, - - - - 226 

Analysis of human urine, - - - 226 

Analysis of guano, - - - - -227 

Analysis of bones of the ox, - - - 227 

Analysis of coal soot, - - - - 227 

Analysis of wool, hair, horns, - - - 228 

Analysis of ox blood and muscle, - - - 228 

Anthelia, . . - - - 151 

Adhesion in machinery, - - - - 254 

Ashes, vitriohc, - - - - - 213 

B 

Bed,* 75 

Basalt, ------ 85 

Botany, - - - - - - 98 

Botany, divisions of, - - - - 93 

Breeze, - - - - - -146 

Bridges, - - - - - - 255 

Biennial roots, - - - - -107 

Buds, - - - - - - 109 

Bole, - - - - - - 169 

Blood, as manure, - - - - 195 

Bones, as manure, - - - - -195 

Butter, quahties of, - - - - 240 

Butter, composition of, - - - - 242 

Butter, chemistry ofj - - - - 241 

Butter, preservation of, - - - - 242 

Buttermilk, cheese from, - - - 241 

Barley, waste as manure, - - - - 202 

C 

Calcium, - - - - - - 165 

Charcoal, animal, - - - - -105 

Chaff as manure, - - - - 200 

Charcoal as manure, - - - - 201 

Carbonate of soda as manure, . - - 207 

Chloride of sodium, or common salt, as manure, - 207 

Chloride of lime and magnesia as manures, - 207 

Crushed rocks, as manure, - - - - 212 



284 INDEX. 

Chalk as a manure, - - - - 213 

Composts, ------ 116 

Comparative value of manures, table of, - 218 

Chemistry, ------ 23 

Capillarity, - - - - - 24 

Cohesion, ------ 25 

Combination, laws of, - - - - 30 

Caloric, ------ 34 

Caloric, expansive power of, - - - 34 

Caloric, conductors of, - - - - 34 

Caloric, specific, - - - - - 35 

Caloric, capacity for, - - - - 35 

Caloric, radiant, - - - - - 35 

Caloric, latent, - - - - - 35 

Caloric, transmission of, - - - - 36 

Cold, 37 

Carbon, ------ 42 

Carbonic acid, - - - - - 43 

Carbonic oxide, - - - - - 48 

Carburetted hydrogen, - - - - 50 

Cerine, ------ 62 

Camphor, ------ 62 

Caoutchouc, - - - - - 61 

Coloring matter, - - - - - 65 

Chlorophylle, - - - - • - 65 

Colors, adjective - - - - -66 

Colors, substantive, - - - - 66 

Carmine, . .... ^ 66 

Chlorine, - - - - - 66 

Compounds derived from the inorganic elements of 

plants, - - - - - 68 

Caramel, ------ 72 

Cleavage planes, - - - - 76 

Clay slate, ------ 87 

Chalk, ------ 87 

Coal, - - - - - ': - 92 

Coal, varieties and origin of, - - - 90 

Coal basin in Wales, - - - - 91 

Class defined, - - - - - 95 

Corolla, -.,..--- 99 

Calyx, - - - . - - 100 



INDEX. 285 

Cotton seed, as manure, - - - - 201 

Cider cake, as manure, - - - - 202 

Cotyledon, - - - - - 103 

Cellular integument, - - - - 110 

Cambium, - - - - - -111 

Cr3'^ptogamous plants, - - - - 112 

Coal waste, as manure, - - - - 212 

Chlorophylle, - - - - - 113 

Climate, - - - - - -]28 

Clouds, - ----- 140 

Corona, - - - - - -150 

Clay, ------ 168 

Colostrum of milk. - - - - 238 

Cream, composition, &c. - - - - 240 

Curd,, how prepared, &c., - - - . 243 

Cheese, qualities of, - - - - 245 

Cheese, manufacture of, - - - - 245 

Cheese, average from milk, &c., - - 246 

D 

Divisibility, - - - - - 25 
Density, ----._ 27 

Diastase, - - - - - 64 
Dip, --..-. 76 

Dyke, 77 

Drift, 79 

Duramen, - - - - - 110 

Digestion, - - - - - -120 

Dissemination of seeds, - - - - 123 

Day, longest in different latitudes, - - 130 

Dew, - - - - - 139 

Draining, its objects, - - - - 183 

Draining, varieties of, - - - - 184 

Dry leaves as manures, - - - _ 200 

Decayed wood as manure, - - - 200 

Dynamics, - - - - - -249 

E 

Elasticity, - - - - - 27 

Equivalent number, - - - - - 31 



286 INDEX. 

Electricit}^, - - - - - 37 

Electricity, vitreous and resinous, - - - 38 

Electricity, negative, - - - - 38 

Electricity, positive, - - - - - 38 

Electricity, conductors of, - - - - 38 

Electrical excitation, - - - - - 38 

Electrical repulsion, - - - - 38 

Electricity, statical, - - - - - 39 

Electricity dynamical, - - - - 39 

Eremacausis, - - - - - - 44 

Elementary bodies, - - - - 54 

Elements, organic, - - - - - 55 

Elements, proximate, - - - - 58 

Elements, immediate, - - - - 58 

Extractive matter, - - - - 65 

Escarpment, - - - - - -76 

Embryo, ------ 96 

Epidermis, - - - - - -98 

Embryo, - - - - - -103 

Epiphytes, - - - - - -107 

Epidermis, - - - - - 110 

Exhalation, - - - - - -119 

Excrements of plants, theory of, - - - 187 

Excrements as manure, - - - - 196 

Excrements, human, - - - - 196 

Excrements of horned cattle, - - - 197 

Excrements of the horse, - - - 197 

Excrements of the hog, - - - - 198 

Excrements of sheep, - - - - 198 

Excrements of birds, - - - - -198 

Epsom salts as manure, - - - - 208 

Earthy manures, - - - - -210 

F 

Fire damp, ----- 50 

Fermentation, - - - - - 70 

Fermentation, vinous, - - - - 70 

Fermentation, acetous, - - - - 71 

Fault, - - - - - - 77 

Formation, - - - - - -77 

Fossil, - - - - - - 77 



INDEX. 287 

Feldspar, composition of, - - - - 88 

Flower, - - - - - -99 

Filament, - - - - - - 101 

Fruit, ------ 102 

Fibrils, - - - - - - 105 

Fusiform roots, - - - - - lOG 

Fibrous roots, - - - - -106 

Faciculated roots, - - - - 106 

Floatino' roots, - - - - -107 

Flowers, terminal, - - . - - 120 

Flowers, axillarj'-, - - - - -120 

Flower, solitary, - - - - - 121 

Forests, their influence on climate and the fall of rain, 136 

Frost, - - - - - - 139 

Frost, .cause of, - - - - 139 

Fogs, - - - - - - 140 

Fire balls, - - - - - 151 

Fallo^ving•, - - - - - -184 

Fallowing, benefits of- - - - 185 

Flesh as manure, - - - - 195 

Fat of animals as manure, - - - 195 

Farm-yard manure, - - - - - 202 

Force defined, - - - - - 249 

Friction, - - - - - - 253 

G 

Gravity, - - - - - - 26 

Gravity, specific - - - - 27 

Galvanism, - - - - - 39 

Gases, properties of - - - - 40 

Gum, - - - - - - 60. 

Gluten, - - - - - - 61- 

Geology, - - - - - 74 

Gorge, •- - - - - -77 

Granite, - - - - - - 83 

Greenstone, - - - - - - 84 

Gneiss, ------ 86 

Graphite, - - - - - - 90 

Genus, defined - - - - - 95 

Germination, - - - - -103 

Granulated roots, - - - - 106 



288 INDEX. 

Gale, - - - - - - 148 

Gypsum, - - - - - 167 

Gelatine as manure, - - - - 196 

Guano, - - - - - - 199 

Green manures, ----- 203 

Green manures, uses of - - - - 203 

Glauber's salts as manure, - - - - 207 

H 

History, natural - - - - - 21 

Hvdroo-en, - - - - - 41 

Hartshorn, spirits of - - ' - - - 55 

Haematoxyline, ----- 66 

Hornblende, slate - - - - - 87 

Hornblende, basaltic, composition of - - 89 
Herbs, ...--- 108 

Hail, ...-.- 142 

Harmattan, - - - - - -147 

Hurricane, - - - - - 148 

Halo, - - - - -. - 150 

Humus, - - - - - - l7l 

Humus, its composition - - - - 179 

Hair as manure, - - - - 195 

Horns as manure, - - - - -195 

Hoofs as manure, - - - - 195 

I 

Isomeric bodies, - - - - - 59 

India rubber, - - - - - 68 

Indigo, ------ 65 

Inorganic elements of plants, - - - 66 

Iodine, ------ 67 

Ideal section of the earth's crust, - - •-SI 

Integument, - - - - . - 103 

Inflorescence, - - - - - 120 

Inflorescence, centripetal - - - 121 

Inflorescence, centrifua:al - - - - 121 

Isothermal lines, - - - - 129 

Isochimenal lines, - - - - -130 

Ignis fatuus, - - - - - 150 



INDEX. 289 

Iron, - - - - - - 161 

Irrigation, - - - - - i8l 

Inclined plane, - - - - - 250 

J 

Joint, - ----- 76 

K 

Kaolin, - - - - - - 76 



Light, - - -• - - - •32 

Light, nature of- - - - - 32 

Light, reflection and refraction of - - - 32 

Light, origin of- - - - - 33 

Light, heating rays of - - - 33 

Lignine, - - - - - ■ - 59 

Lava, - - - - - - 85 

Limestone, primary - - - - 88 

Latex, - - - - - -110 

Liber, - - - - - - no 

Leaf, - - - - - - 113 

Leaves, deciduous - - - - 113 

Leaves, evergreen - - - - -113 

Leaves, scattered - - - -■ 113 

Leaves, alternate - - - - 113 

Leaves, opposite - - - - -113 

Leaves, verticilate - - - - 113 

Leaf, orbicular - - - - -114 

Leaf, ehptical - - - - - 114 

Leaf, lanceolate - - - --114 

Leaf, .cordate - - - - - 115 

Leaf, sagittate - - - - - 115 

Leaf, reniform - - - - 115 

Leaf, linear - - - - - 115 

Leaf, deltoid - - - - -115 

Leaf, acerose - - - . - 115 

Leatj pinnatified - - - - -115 

Leaf, connate - - - - - 116 

Lea^ digittate - - • . -116 



290 INDEX. 

Leaf, stellate ^ - - - - 116 

Leaf, lobcd - - - - -116 

Leaf, compound - - - - ll7 

Leaf, sinuate - - - - -Tl7 

Leaf, emarginate - - - - 11 7 

Leaf, tubulate - - - - -ll7 

Leaves, ternate - •• - - 117 

Leaves, bitcrnate -- - - -117 

Lightning rods, - - - - - 143 

Lightning, - - - • - - 143 
Lightning, conditions under which it is developed, &c. 144 

Land and sea breezes, - - - - 140 

Lime, - - - - - -165 

Lapping, - - - - - l79 

Leached ashes as manure, - - - - 211 

Lime as manure, - - - - 213 

Lime, mode of applying - - - - 214 

Lever, ----- - 250 

Latex, - - - - - -110 

M 

Myricine, - - - - - -62 

Mordant, ----- 65 

Mica slate, - - - - - -87 

Mica, composition of - - - - 89 

Midrib, - - - - - - 113 

Meteorology, - - - - - 125 

Meteor, - - - - - - 127 

Mists, --.-.- 140 

Monsoons, - - - - - -148 

Mirage, - - - - - - 152 

Meteorites, - - - - - -153 

Manganese, - - - - - 161 

Magnesium, - - -- - -164 

Magnesia, - - - - -164 

Marl, 166 

Manures, - - - - - 193 

Manuring, objects of - • -'-194 

Manures, animal - - ' - 195 

Mineral manures, - -# - - -207 

Marl as manure, - - - - 212 



INDEX. 291 

Milk, properties of- - - --23V 

Milk, composition of- - - - 238 

Milk, quality of how affected - - - 238 

Milk, quantity how affected - - - 239 

Milk, separation of its elements . _ - 240 

Milk, modes of curdlino- _ _ _ 243 

Milk, its uses in the animal economj'-, - - 244 

Milk, alcoholic spirit and vinegar of - - 247 

Mechanical philosophy, - - - - 249 

Machinery, objects of - - - - 250 

Machinery, on regulating motion of - - - 251 

Motion, species of - - - - 252 

Machinery, obstructions to the action of - - 253 

Materials, strength of - - - -253 

Materials, beams and columns - - - 255 
Materials, cyhnder ----- 255 

Materials, metals, - - - - 256 

Materials, wood, - - - - -256 

Materials, stone, - - - - - 257 

N 

Nitrogen, - - - - - 45 

Napiform roots, - - - - -106 

Nerves, - - - - - - 113 

Night soil, - - - - - -196 

Nitrate of soda as manure, - - - 208 



Oxyo-en, - - - - - -41 

Oxalic acid, - ... - - 49 

Organic bodies, mutual relation of - - - 61 

Oils, fixed - - - - - 63 

Oils, volatile - - - - - 63 

Organic elements, metamorphosis of - - 71 

Outcrop, - - - - - -76 

Olivine, - ' - - - - - 85 

Order defined, - - - - - 95 

Ovary, - - - - - - ]01 

Ovules, - - -- - -101 

Oil cake as manure, - - - - 201 



29^ IKDET. 



Philosophy, natural, - - - - 21 

Physics, - - - - - -21 

Prism, ------ 33 

Pryogen, - - - - - -39 

Phosphorus, - - - - - 67 

Phosphoric acid, - - - - - 68 

Primary rock, ----- 74 

Porphyry, ------ 84 

Plants, divisions of, - - - - 94 

Plants, classification of - - - - 94 

Plumule, ----- 96 

Pistils, - - - - - -99 

Perianth, - - - - - 99 

Petals, ------ 99 

Pollen, ------ 100 

Placenta, - - * - - -101 

Pericarp, - - - - - 102 

Parasites, - - - - - -107 

Perennial roots, ----- io7 

Pith, ------ 109 

Parenchyma, - - - - - 118 

Peduncle, - - - - - -121 

Panicle, - - - - - - 121 

Plants, curious phenomena of - - - 124 

Plants, locaUty of - - - - 125 

Plants, diseases of- - - - -125 

Parhelia, - - - - - 151 

Paraselense, - - - - - -151 

Potassium, - - - - - 163 

Potter's clay, - - - - - 169 

Pipe clay, - - - - - 169 

Peat, ' - - - - - - 170 

Peat, composition of- - - - 170 

Paring and burning, - » - - 182 

Phosphate of hme, - - - - 196 

Peat as manure, - - - - -201 

Pasture, improvement of the soil by - - 205 

Pasture, temporary - - - - - 205 



INDEX. 293 

Pasture, permanent, - - _ 205 

Power defined, - - - - -249 

Pulley, ------ 250 

a 

Q.aartz, - - - - - - 86 

E 

Rarity, ------ 27 

Resin, ------ 62 

Rocks, classification of - - - - 77 

Rocks, aqueous - - - - - 80 

Rocks, volcanic - - - - - 81 

Rocks, plutonic - - - - - 81 

Rocks, metamorphic - - - - 81 

Rock salt, ------ 89 

Radicle, ------ 96 

Receptacle, - - - - - -98 

Radicle, -- - - - - 103 

Root, - - - - - - 104 

Ramose roots, - - - - - 105 

Root, functions of- - - - -108 

Respiration, - - - - - 120 

Rachis, - - - - - - 121 

Rain, - - - - - - 137 

Rain, its cause, - - - - - 137 

Rain, its quantity, (fee, - - - - 137 

Rain tables, - - - - -138 

Rainbow, -- - - - - 152 

Riiinbow, inverted - - - - -152 

Ribbing, - - - - - 180 

Rotation of crops, - - - - -186 

Rotation, objects of - - - - 187 

Rotation, courses from Colman, - - - 189 

Rotation, courses of - - - - 190 

Rennet, uses and preparations of - - - 244 

S 

Science, natural - - - - 21 

Synthesis, - - - - - - 23 



294r INDEX. 

Sugar, ------ 29 

Spectrum, solar - - - - - 33 

Salts, properties of - - - - 67 

Salts, acid - - - - - -57 

Salts, neutral - - - - - 57 

Salts, basic ------ 67 

Salts, double - - - - - 57 

Salts, effervescent, - - - - - 57 

Salts, deliquescent, - - - - 68 

Starch, .----. 59 

Sulphur, - _ - - - 67 

Stratification, • - - - - 75 

Seam, --.--- 76 

Syenite, - - - - - 81 

Serpentine, - - - - - 85 

Sandstone, - - - - - 87 

Slate, talcose, - - - - - 88 

Species defined, - - - - - 95 

Stamens, - - - - - 99 

Style, ..--.. 101 

Stigma, - - - . . - - 101 

Seed, - - - - - - 103 

Spongioles, - - '- - - 105 

Shrubs, ------ 108 

Stem, exogenous - - -r - 109 

Sap, - . . - . - - 110 

Scape, ------ 121 

Seeds, longevity of - - - - - 124 

Snow line, - - - - - 130 

Snow fines, table of - - - - 131 

Soils, products of - - - - 136 

Snow, -___-- 141 

Snow, red and green, - - - - 141 

Snow crystals, system of - - - - 142 

St Elmo's fire, - - - - - 144 

Simoon, ------ 148 

Sirocco, - - - - - - 148 

Shooting stars, - - - - - 153 

Silicon, - - - - - - 158 

Sodium, ------ 169 

Stalagmites, - - - - - 162 

Stalagmites, - - - - -168 



INDKX. 295 

Spar, ------ 168 

Soils, physical properties of - - - 173 

Soils, weight of - - - - ]73 

Soils, state of division of - - - - 173 

Soils, firmness and adhesiveness of - - 173 

Soils, power of imbibing water - - - l74 

Soils, power of containing water, - - 174 

Soils, power of retaining water, - - - 175 

Soils, capillary power of - - - 175 

Soils, their contractibility on drying, - - l76 

Soils, their power of absorbing gaseous matters, 176 

Soils, their power of absorbing heat, - - l76 

Soils, their power of retaining heat, - - 177 

SoilSf their power of radiating heat, - - l77 

Soils, their ultimate uses to plants, - - 177 

Subsoil ploughing, - - - - - 180 

Stitching, - - - - - 180 

Scarifying, - - - - - -180 

Stercology, - - - - - 193 

Skins of animals as manure, - - - 195 

Straw as manure, - - - - 200 

Saw dust as manure, - - - - 200 

Soot as manure, - - - - 201 

Saline manures, ----- 207 

Sulphate of soda as manure, - . - 207 

Sulphate of lime, or gypsum, as manure, - - 208 

Silicates of potash and soda as manures, - 209 

Salts of ammonia as manure, . . - 209 

Sea sand as manure, - - - - 213 

Screw, - - - - - - 250 

T 

Tenacity, - - - - - 28 

Tannin, . . . . ~ - Q5 

Tertiary strata, - - - - - 79 

Transition rocks, - - - - - 79 

Trachyte, - - - - -84 

Tissue, cellular - - ^ - - - 97 

Tissue, woody - - - - - 97 

Tissue, vasiform - - - - - 97 

Tissue, vascular - - - - 97 

Tissue, laticiferous - - - - - 98 

Tap root, - - - - - 105 



296 INDBX. 

Tuberous roots, - - - - - 106 

Trees, ----.. 109 

Tendrils, - - - - - -122 

Temperature, how to attain tlie mean - - 131 

Temperature, table of - - - - 132 

Thunder, - - - - - 144 

Thunder, cause of - - - - - 144 

Trade winds, - - - - - 147 

Tornado, - - - - - -148 

Tillage, objects of - -. - - 179 

Trench ploughing, - - - - -180 

Tillage, varieties of - - - - 181 

Tanner's bark as manure, - - - - 201 

Top dressing for crops, - - - 203 

U 

Urine as manure, - - - - 199 

Urine, waste and value of - - - - 200 

Urine of hog and goat, - - - - 229 

V 

Vein, - - - - - - 77 

Variety defined, ----- 96 

Veins,^ - - - - - - 114 

Venation, - - - - - 114 

W 

Water, - - - - - - 46 

Wax, -----. 96 

Wells and Springs, - - - - - 91 

Wood, ------ 109 

Weather, - - - - - -127 

Whirlwind, - - - - - 148 

Warping, - - - - - - 181 

Wood ashes as manure, - - - - 210 

Whey, qualities of- - - - -245 

Wheel and axle, - - - - - 250 

S? - ■ - -11^-70 9 M . - III 

Wool as manure, - - . - . 195 

X 

Xanthine, - - - - - '65 

Y 

Yeasty - - - - - - 7q 






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